With some built-in validation checks like those noted above, that would work for me.
As far as I am concerned, it should never be possible for anyone (curator or not) to save a change to Introduced when any of the descendant places will remain set to Native or Endemic for that taxon. That creates a logical inconsistency in the system.
And really, setting something to Introduced when it will remain as Unknown in descendant places is logically inconsistent also (probably why that automatic behavior changing them to Introduced was implemented in the first place).
ADDED BOOKKEEPING NOTE: related feature request here
https://forum.inaturalist.org/t/adding-species-to-checklist-should-cascade-up-the-geography-hierarchy/1838