Hello,
I have two issues here with the Heal spells and the Heighten Spell Metamagic.
First, Heighten Spell affects Heal.
This makes sense when used on undead as they have to make a save.
But I am using it much more often on allies and there it bothers me that I have to pay the cost of heighten even though they dont make a save.
That are 15 wasted SP.
It is annoying to turn on heighten and often other metamagics too to cast offensive spells and then having to turn it off again to not waste spell points in healing.
I noticed that you are making a fix for undead resisting to benficial spells and wondered if you could do something similar to make Heal not heightened when cast on allies.
Second, while the unheightened spells show the correct DC, their heightened counterparts display a lower number (like if the spell level was 0 instead of 9).
I have yet to verify whether this is a display error or a broken application of heighten.