I guess one detail I left out about the roof in general; we plan on selling house in a few years; so longevity isn't a major concern. I do know that a 2nd layer isn't ideal, but it is allowed by code, and makes planning around weather, and work; doing a few 100 sf in the evening easier.
Yes, I know as an Owner-Builder, in FL, you can't sell within 1 year of pulling an Owner-Builder permit. You can't pull your own permit for the purpose of rent, sale, ect and if you sell within 1 year, your considered to have done the work for the ourpose of sale.
There is one soft spot, around a bathroom pipe boot that is soft, that will get OSB removed and replaced (not covered by my building permit).
Building permit was very simple (I work in a permit related field, but not building permits or county, state stuff) hand filled details, Shingle "FL#", they confirmed I owned property, pay my $84, and walked out with my permit.
Edit: the soft spot will get felt and doubled shingles as well, so as to not have an uneven area, drawing attention to the replaced OSB