It essentially kills rerolling GCs with PGems. It would allow getting skillers much easier, just reroll prefix. And after you’ve got the skiller you want you can try to reroll the suffix on it… so definitely no on charms, makes it too easy.
It would also let you kinda reliably obtain Jewelers Tiara of Speed\Monarch of Deflection\Light Plate of Whale; 6\40 javelins too; and even those crazy magic jewels like +30 Max or 40\15. Not sure how I feel about such a big boost to availability of these legendary magic items. Maybe if it needed a few more resources than just 1pgem and 1 small rune - then i’d be ok. Or maybe if you only had 33% chance to actually roll the prefix or the suffix (i.e. it could roll blank!).
I also had a related idea with rerolling magic items, it’s on the lower end and might be helpful but not overpowered because of the ilvl limit; but might produce some cool useful items for lower levels and some still hard to obtain chase items.
Just not keys please. Keys shouldn’t be hoarded, they should be used or traded off.