These are the 2 ways to regen the source files in Reaper:

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It's not using AHK scripts to access Biab functions like the Track Injector, all the scripts are internal Reaper Lua scripts that millions of users use.
The slow MultiPicker on initial start can be fixed by PG so it's not scanning every file you have in the RealTracks and Drums folders, when you Rebuild it should already have a database.
I have been through 15 years of the issues you bring up, if someone told me back then I could just do this or that it would of saved me so much stress, but no one told me they just all did things the long, hard and frustrating way, they thought that was the only way possible, now most are stuck repeating this because it's how they have done it for so long, so anything new is scary.
Because of all the stress and frustration this cause me to do a deep dive and come up with easy ways to do all this without having thousands of consolidated wav files on hard drives.

The font in the AEW timeline can be changed so easy by PG, but they could be working on direct chord edit on it now if they are not already working on the Mac version. I will have a look in the code and see if I can find it.