Using environment variable during another environment variable definiton in flow properties - issue

[jopl]

Dear Colin,
thanks again for quick and valuable advise, I am using already this approach .
Unfortunately, it is not easy to do in case of mqtt in node, as there is no input option (except mqtt itself) and therefore setting up the parameters by code is impossible (or I am not experienced enough).
And what is frustrating for me ... as description of using environment variables on link Using environment variables : Node-RED says, it should be possible in TypedInput widget (like flow properties are) ... and there is indicator it is / was possible: Using subflow environment variable to set mqtt topic - #7 by tinamore ... knolleary used this and tinamore confirmed it is / was working ...
Therefore, is it relating to version of my NodeRed? Or was the attitude of knolleary solution misleading?
Hmmm ... still unclear for me.
Regards, Josef.