Thanks for the ups patch.
The problem was reproduced.
It seems like a bug in SkillSystems.
If you make a statbooster that raises the upper limit of HP and recover with heal, it will recover ignoring HP's upper limit.
It does not occur in vanilla.
It occurs when I insert SkillSystem.
It occurs in both SkillSystems 20171130 and SkillSystems 20180214.
It also occurred on the boss rush stage of the latest version skill system downloaded from github.
I think that this is not a problem of FEBuilderGBA.
I gave a bug report to SkillSystems.
I think that bugs will be fixed in the future,
In the current SkillSystems, please do not make items to increase HP if equipped.