Per my comment on this video on YT, I think much of this choice will depend on what Nick wants to mainly use the racquet for in the near future.
If competitive play remains even a passive priority, then there's a very real chance that, as anticlimatic as it would be, Nick simply chooses the '21 PD+ (and loads up on as much outgoing stock as he can get). As long as he's not too sour on Babolat and/or committed to picking a new brand from the get-go, then this choice is as probable as anything else, if not more so.
If usability for coaching is the primary intent, then the Percept 100 may very well be his choice, for if you watch all of the play test videos, I think it's fairly obvious that he was hitting by far his most consistent and highest average quality ground stroke with the P100. This would translate into better quality feeding for his students, with less effort/focus/fatigue required. A very real consideration.
Lastly, a bit of image-consciousness. If marketability is a factor at all, Nick may choose Tecnifibre, as much for the all-white cosmetic as for their novelty and up-and-coming-ness. To give credit where credit is due, though, among all the white-colored frames, the TFight 300 would probably make the most sense anyways, as it would offer more reliable overall behavior than the Shift and be a bit more forgiving than both Shift and WhiteOut.
Overall, I predict he'll place most of his decision weight on actual playability (so, competitive and/or coaching), but there will be a healthy dose of image-consciousness thrown in there as well. As for a prediction, I'm honestly stumped at this point, mainly due to his overall tone so far. Regardless, I'm sure the concluding episode will be a good one.