There seems to be a bug in JSONata/Change node.
I can set the inject to payload["000104391731"].state.remainingTime[0] = 2
but JSONata or change node can not see it, but it visable in debug.
example change JSONata flow
[{"id":"8b40e32d.d25c28","type":"inject","z":"8d22ae29.7df6d","name":"","props":[{"p":"payload[\"000104391731\"].state.remainingTime[1]","v":"45","vt":"num"},{"p":"topic","vt":"str"},{"p":"payload[\"000104391731\"].state.remainingTime[0]","v":"2","vt":"num"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":170,"y":1880,"wires":[["15adae6d.934902"]]},{"id":"15adae6d.934902","type":"change","z":"8d22ae29.7df6d","name":"","rules":[{"t":"set","p":"hold0","pt":"msg","to":"payload[\"000104391731\"].state.remainingTime[0]","tot":"msg"},{"t":"set","p":"hold1","pt":"msg","to":"payload[\"000104391731\"].state.remainingTime[1]","tot":"msg"},{"t":"set","p":"timestrin","pt":"msg","to":"$string(hold0) & 'h ' & $string(hold1) & 'min'","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":260,"y":1940,"wires":[["5e1bd60c.64727"]]},{"id":"5e1bd60c.64727","type":"debug","z":"8d22ae29.7df6d","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":580,"y":1960,"wires":[]}]