I say this as someone who has quite a few TAs maxed out and finished both Stage 1 and 2 Showdowns quite a few times:
Stage 1 Showdowns need to be altered.
It's just goofy that the 2nd Boss in Stage 1 is far harder than anything in Stage 2. I have no problem grinding Showdowns like I've done for Stage 2 to get the cards I'm aiming for, but it seems so dumb that to get through Stage 1 TA we (theoretically) have to do a harder Showdown 3x vs doing an easier one 2x for Stage 2 TA.
Combine that with the fact that MTO isn't worth the time anymore and the FOTF cards being obsolete within the next month of the game, and there's just so little motivation left to go back and complete other teams' programs.
I think they need to adjust the difficulties on Stage 1, change the stat achievements to be more like Stage 2 where you often don't have to play whole games, and just make it a more feasible way to build a foundation for Affinity programs moving forward. I'd really rather grind than do countless exchanges, it's just not worth it at the moment.