Mission completed! All issues have been solved! Thanks for your help!
At the end I was able to change the output of the node which switches off the device and sent that message back to the cron plus node. The final version of the flow looks like this:
The end result in Home Assistant look like this:
[{"id":"30e9e18e08e63fd3","type":"tab","label":"Flow 2","disabled":false,"info":"","env":[]},{"id":"5b910241fcc70820","type":"cronplus","z":"30e9e18e08e63fd3","name":"","outputField":"payload","timeZone":"","persistDynamic":false,"commandResponseMsgOutput":"fanOut","outputs":4,"options":[{"name":"on_sched","topic":"on","payloadType":"json","payload":"{\"state\": \"on\"}","expressionType":"cron","expression":"0 30 14 ? * WED *","location":"","offset":"0","solarType":"all","solarEvents":"sunrise,sunset"},{"name":"off_sched","topic":"off","payloadType":"json","payload":"{\"state\": \"off\"}","expressionType":"cron","expression":"0 30 14 ? * WED *","location":"","offset":"0","solarType":"all","solarEvents":"sunrise,sunset"}],"x":180,"y":240,"wires":[["8f9f537a4c75e40d"],["e9da367b335dbe12"],[],["fa5b15823dd7afe6"]]},{"id":"106cbe4819f840f1","type":"function","z":"30e9e18e08e63fd3","name":"Date Next Run","func":"\nconst next = msg.payload.result.reduce((a, b) => a.status.nextDate < b.status.nextDate ? a : b)\nmsg.payload = {\n name: next.config.name,\n topic: next.config.topic,\n next: next.status.nextDate,\n nextLocal: next.status.nextDateTZ,\n timeZone: next.status.serverTimeZone,\n when: next.status.description,\n msUntil: next.status.nextDate.valueOf() - next.status.serverTime.valueOf(),\n description: next.status.nextDescription,\n}\n\n\n\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":360,"y":320,"wires":[["5bca6964d1a2a3a5"]]},{"id":"0a75e7b008ae1c95","type":"api-call-service","z":"30e9e18e08e63fd3","name":"Date & Time","server":"ab0c7805.ea8858","version":5,"debugenabled":false,"domain":"input_text","service":"set_value","areaId":[],"deviceId":[],"entityId":["input_text.tuin_beregening_datum_tijd_volgende_run"],"data":"{\"value\":\"{{payload}}\"}","dataType":"json","mergeContext":"","mustacheAltTags":false,"outputProperties":[],"queue":"none","output_location":"","output_location_type":"none","x":710,"y":320,"wires":[[]]},{"id":"5bca6964d1a2a3a5","type":"change","z":"30e9e18e08e63fd3","name":"","rules":[{"t":"set","p":"payload","pt":"msg","to":"$moment(msg.payload.next).lang(\"nl\").tz(\"Europe/Amsterdam\").format('lll')","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":540,"y":320,"wires":[["0a75e7b008ae1c95"]]},{"id":"21f1db9f6ca0572e","type":"api-call-service","z":"30e9e18e08e63fd3","name":"Pomp: Uit","server":"9d8c9ade.d8af7","version":5,"debugenabled":false,"domain":"homeassistant","service":"turn_off","areaId":[],"deviceId":[],"entityId":["switch.tuin_verlichting"],"data":"","dataType":"json","mergeContext":"","mustacheAltTags":false,"outputProperties":[{"property":"topic","propertyType":"msg","value":"status-all","valueType":"str"}],"queue":"none","output_location":"","output_location_type":"none","x":640,"y":240,"wires":[["5b910241fcc70820"]]},{"id":"b45fe18073ee5efd","type":"api-call-service","z":"30e9e18e08e63fd3","name":"Pomp: Aan","server":"9d8c9ade.d8af7","version":5,"debugenabled":false,"domain":"homeassistant","service":"turn_on","areaId":[],"deviceId":[],"entityId":["switch.tuin_verlichting"],"data":"","dataType":"json","mergeContext":"","mustacheAltTags":false,"outputProperties":[],"queue":"none","output_location":"","output_location_type":"none","x":630,"y":160,"wires":[[]]},{"id":"8f9f537a4c75e40d","type":"api-current-state","z":"30e9e18e08e63fd3","name":"Automatische beregening: Aan?","server":"ab0c7805.ea8858","version":3,"outputs":2,"halt_if":"Aan (ma, wo, vr, 07:00-08:00)","halt_if_type":"str","halt_if_compare":"is","entity_id":"input_select.tuin_beregening_automatisch","state_type":"str","blockInputOverrides":false,"outputProperties":[{"property":"payload","propertyType":"msg","value":"","valueType":"entityState"},{"property":"data","propertyType":"msg","value":"","valueType":"entity"}],"for":0,"forType":"num","forUnits":"minutes","x":410,"y":160,"wires":[["b45fe18073ee5efd"],[]]},{"id":"e9da367b335dbe12","type":"api-current-state","z":"30e9e18e08e63fd3","name":"Automatische beregening: Aan?","server":"ab0c7805.ea8858","version":3,"outputs":2,"halt_if":"Aan (ma, wo, vr, 07:00-08:00)","halt_if_type":"str","halt_if_compare":"is","entity_id":"input_select.tuin_beregening_automatisch","state_type":"str","blockInputOverrides":false,"outputProperties":[{"property":"payload","propertyType":"msg","value":"","valueType":"entityState"},{"property":"data","propertyType":"msg","value":"","valueType":"entity"}],"for":0,"forType":"num","forUnits":"minutes","x":410,"y":240,"wires":[["21f1db9f6ca0572e"],[]]},{"id":"e6e8680f76376f6b","type":"api-call-service","z":"30e9e18e08e63fd3","name":"Date & Time","server":"ab0c7805.ea8858","version":5,"debugenabled":false,"domain":"input_text","service":"set_value","areaId":[],"deviceId":[],"entityId":["input_text.tuin_beregening_datum_tijd_laatste_run"],"data":"{\"value\":\"{{payload}}\"}","dataType":"json","mergeContext":"","mustacheAltTags":false,"outputProperties":[],"queue":"none","output_location":"","output_location_type":"none","x":390,"y":440,"wires":[[]]},{"id":"fa5b15823dd7afe6","type":"function","z":"30e9e18e08e63fd3","name":"","func":"var now = new Date().toLocaleString(\"nl\", { year: 'numeric', month: 'numeric', day: 'numeric', hour: '2-digit', minute: '2-digit', hour12: false });\nreturn { payload: now };\nreturn msg;\n\n","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":235,"y":440,"wires":[["8c3fb5f13903a5cc"]],"l":false},{"id":"8c3fb5f13903a5cc","type":"change","z":"30e9e18e08e63fd3","name":"","rules":[{"t":"set","p":"payload","pt":"msg","to":"$moment(msg.payload.next).lang(\"nl\").tz(\"Europe/Amsterdam\").format('lll')","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":360,"y":380,"wires":[["e6e8680f76376f6b"]]},{"id":"a2adb87ef24caa47","type":"comment","z":"30e9e18e08e63fd3","name":"Option 3","info":"","x":320,"y":520,"wires":[]},{"id":"ab0c7805.ea8858","type":"server","name":"Home Assistant","version":4,"addon":true,"rejectUnauthorizedCerts":true,"ha_boolean":"y|yes|true|on|home|open","connectionDelay":true,"cacheJson":true,"heartbeat":false,"heartbeatInterval":30,"areaSelector":"friendlyName","deviceSelector":"friendlyName","entitySelector":"friendlyName","statusSeparator":"at: ","statusYear":"hidden","statusMonth":"short","statusDay":"numeric","statusHourCycle":"h23","statusTimeFormat":"h:m"},{"id":"9d8c9ade.d8af7","type":"server","name":"Home Assistant","version":4,"addon":true,"rejectUnauthorizedCerts":true,"ha_boolean":"y|yes|true|on|home|open","connectionDelay":true,"cacheJson":true,"heartbeat":false,"heartbeatInterval":30,"areaSelector":"friendlyName","deviceSelector":"friendlyName","entitySelector":"friendlyName","statusSeparator":"at: ","statusYear":"hidden","statusMonth":"short","statusDay":"numeric","statusHourCycle":"h23","statusTimeFormat":"h:m"}]