The stacking rules probably prevent psychofeedback from boosting other scores twice. This takes the raw power down from 600% of what the designers expected to, at maximum 100%, probably less depending on your stats. Specifically:
Otherwise a mind mage can use the boosted scores from a previous manifesting to then boost a second stat. Then wait for your bound naberius [ToM] to heal you up to full and swap both boosts BACK. Keep doing it back and forth until capped by your ML. You don't even need to change form into a high physical stat creature first. It works right out of the box!
You end up with all 3 physical scores being boosted by your ML (which is over 100 due to circle magic + psiotheurge feats + shards) ... every day for the full day (thanks for persistent power).