learning REXX will certainly give You a different perspective of <data> processing
since I suppose it will also deal with ISPF dialog development
the combination is certainly a good add on for Your skill portfolio
I would be happy to jump on it, but ....
as usual these opinions and judgement are strictly personal
for example I find a REXX skill useful also for the <standard> programmer
it is the quickest tool that You could find for easy prototyping
look at some tools developed in rexx ...
for example XMITIP and TXT2PDF
try to redo them in COBOL
as I said a completely different perspective