Can a character with levels in Mind Mage and Spell-to-Power Erudite learn their own spells (i.e. Shapechange) as powers at a below normal spell level (i.e. 1st level) with the Mind Mage's Focus of Discipline class ability which allows them to cast spells as lower level spells using lower spell slots? Perhaps if they created a magic item with the lowered spell and then studied that or something?
Based on my understanding, being able to use a class feature to cast a spell or manifest a power at lower level, doesn't change what level spell or power it actually is, only it's effective spell level for purposes of memorizing, casting, or manifesting.
Note also that the class feature in question says:
...counts as a correspondingly lower-level effect for the purposes of dispelling, saving throw DC, and identification for counter spelling.
Those are the only other purposes it counts as a lower level effect for.
If it had said that it counts for purposes of scribing a scroll or encoding a power stone, you would have been in business.