no, I tried it and it does not diminish me from hp, when you want to change a pokemon you do not see the hp in 999, you only see 999 in the fight and I do not diminish anything of hp. It works on my perfect switch.
[Pokemon Slot 2 Health 999]
041F0000 8D46F2D4 000003E7
[Pokemon Slot 3 Health 999]
041F0000 8D46FA74 000003E7
[Pokemon Slot 4 Health 999]
041F0000 8D470214 000003E7
[Pokemon Slot 5 Health 999]
041F0000 8D4709B4 000003E7
[Pokemon Slot 6 Health 999]
041F0000 8D471154 000003E7
creidts to
@Kc57