And for the record, if the Pokémon's origin isn't a SV game, then absolutely no.
The HT/WT/Scale was GIVEN BY HOME. It is generate/rerolled in HOME. It has the data before it even enters SV.
No offense, I think you have no idea what you're saying, and might be unconsciously bending known facts to fit your mental narrative, to justify you being able to whatever size you want. It is likely an unconscious cognitive bias, and not a personal attack. Just pointing it out before you fully commit to that train of thought.
It is true that if a mon was caught/bred in SV, HOME would absolutely have no way of knowing what size it was supposed to have before entering SV, but then you encounter a different breed of issues: the size is defined by RNG, and what if that RNG state was correlated, and became public knowledge after? Changing HT/WT/Scale could break that.
A lot of people in Gen 8 didn't know there were RNG correlations (cause at that time it wasn't discovered), and all the edits became illegal.
So both sides (pre-HOME and post-HOME) of the coin you're causing trouble for yourself.
Literally keeps tracks of data structures. HOME probably doesn’t assign the space for every piece of data to a user, but instead give all of them a list of trackers regarding what mons a user has, done for space saving purposes. In any case I’m not too interested in discussing how to beat HOME’s TOS; this feels like it’s slowly moving to that direction.
You probably shouldn’t. When a HOME Tracker changes (if it mutates data from a previously valid tracker), it Carries forward all valid data from the previous tracker. That said, HOME could easily bring forward the previous tracker too, making a chain of trackers. Meaning they can follow the chain to find the first entry point, and see who is the first device that brought stuff over.
I feel like I've already tackled the original queries, plus more, in this thread.
Any last questions from the people that are in this thread, before I lock this thread?