Thats very good that someone takes care of this nice peace of code,
but I'm afraid the golden days of Jcl had been gone for a while.
Meanwhile Delphi, System, RTL, RTTI has improved much, and also added their own native Linux cross-platform support.
What I would suggest is to check and cleanup the code a little, to find the golden nuggets that were worth to be unraveled ( I'm sure there are many ).
Who is using Jcl / Jvcl actively, who can give some hints ?
If Jedi would not be such a big unsorted mess I would like to look deeper into this too,
but I always have the bad feeling that it brings more overhead than it brings useful features.
Maybe you have some deeper insights, and you can explain what features especially should stay and which one should be separated ?
To have a general, external library that could fill some gaps of Delphi would be a good idea, in my opinion, but it should be directly VCL/FMX ready, not especially platform binded.