I've just posted a new extension to the forge https://forge.fantasygrounds.com/shop/items/719/view
This enables the DM to remove the last damage/heal done to a character.
It should also reinstate any removed effects due to death or concentration fails on the target character, and also reinstate effects that the character was concentrating on that are on other characters.
As ever, let me know if you find any issues.
(I *think* it should work with the extra hitpoints granted by Rhagelstrom's Arcane Ward extension also)
Cheers, Steve.