Bard "Jack Of All Trades" ?

[LordEntrails]

Because CHECK:[HPRF] also gives you half proficiency to skills; so you'll get double proficiency bonus on skills if you also make them half proficient.

Yea, don't add an effect, just change the skill tab on the character sheet. Am I missing something?
Like this:
Screenshot 2023-04-02 103331.png

[Zacchaeus]

Yes. Jack of all Trades gives you half proficiency bonus on all ability checks. So if you make a strength check, for example, you get a half proficiency bonus - so you need CHECK:[HPRF] in order to do that (or I suppose you could just put a figure in the modifier box - or you could also put that effect on just before you make the check and make the effect be removed on next roll). You would also need an INIT:[HPRF} effect for initiative rolls if you don't use CHECK. SO I'd go with the CHECK and then remove the bonus from proficient skills. It's a bit long winded, sure. But it's fire and forget rather than any alternative approach.

[LordEntrails]

Ah, ability checks, not just skill checks. Too often I forget to distinguish between the two