I'm in favor of adding more APPs/PPPs. That being said, what "hole" would you seek to fill among the HEATs or VEATs? IMO, the APPs/PPPs are meant to give regular ATs things that they don't normally have access to, but the Epic ATs aren't really lacking in any one area...
EDIT:
After some thought, here's a few ideas as to how the Epic Power Pools could be handled in a slightly different way for those special ATs:
For Khledians, add some powers that are usable in all forms, but behave slightly differently depending upon which one you are in.
For VEATs, maybe play against type and offer a PBAoE or single target ally heal, etc.