Pete,
Thanks for trying XTads. (And for building it, also; I don't expect many people will do that.)
Missing .tcp files:
I'll look into that. Frankly, the ...-src.zip file contents haven't been tested on a Mac other than my main one. Some cruft or unnecessary files may have crept in.
Demanding games:
I've tested every T2 and T3 game that I can find in the IF Archive, but it's been a few months since I looked for new games there. If you could try games from late 2016 and 2017, you'd probably cover games I haven't. (By "tested" I mean started up, run a few typical commands, obvious meta-commands, help menus, etc.)
A couple of games that I consider demanding would be 1893.gam (T2) and videobar.gam (T2). (The latter features an ASCII art animation. I think the crucial command is "put video tape in vcr" or some such.)
Also check out the home page,
https://xtadsetc.com
(Rune's my first name btw - no Mr needed :-))
- Rune