True that ...
I was focused on basics.
//Edit:
That said, I think that we would lose nothing and it would not be overpowered in the slightest if Sorcerer's draconic resilience did not have that caveat, and could function as a 'baseline' option at any time. It wouldn't hurt balance overmuch in this particular case.
You mean ...
Make it possible to have basic Leather Armor (11AC), but still calculate with 13AC+Dex from inheritated Scales?
I gues that would really lose nothing ...
On the other hand, concidering that most "armors" providing good bonuses for Sorcerers would be (most likely) clothing anyway, im not really sure why bother.
