ReignOfComputer

Load a save file and set it to a slot a box.

Appear Legal, yes.

https://projectpokemon.org/home/forums/topic/40006-issues-with-pkhex-read-this-first-swsh-update/

That's not a workaround. That's just illegal. Whether the game thinks its Legal or not.

Wrong game. Partner Cap Pikachu is for Ultra Sun/Moon.

https://projectpokemon.org/home/forums/topic/56296-read-home-tracker-value/

If you want to clear it just put a single 0 (or as many zeros as you want to enter). Using the entire field is fixed as of latest commit and will be in next release.

Gen 8 -> Home -> Gen 8 also assigns a tracker. As long as it touches Home.

.HeldItem=Gold Bottle Cap Spell it out properly?

If I understand Kaph correctly, any Pokemon entering Home that doesn't already have a tracker (0000....) will be assigned one.

Fixed in latest commit, wait for next release.

That's the Classic Ribbon. Same idea in all previous games.

Wait for GameFreak to update their checks.

It's hacked. Migrated Pokemon have 0 Height/Weight.

We're not GameFreak/etc, only they know the extent of checks performed on said tracker both present and future. It wouldn't be difficult to trace origins, though I highly doubt it will result in a ban (don't quote me on this). It's not feasible for them to trace if someone has decided to spam hacks via surprise/local trades, for example. It's possible flagged Pokemon will just not be able to work with Home down the road, but this is all just speculation.