Normally I'd agree with this. And to prove this, I'm going to disagree with this (this time)...
FK1000P is quite solventy, so it'll remove some/most of the Black Hole. If it were a wax, I'd agree with you Dan, but not for a sealant.
OP, I'd also suggest that whilst FK will happily last 3months+ on a bare surface, the Black Hole is going to reduce it's durability considerably. FK isn't designed to sit on top of an oily glaze so it'll struggle to last 3 months, TBH. Either go with a decent wax or replace the Black Hole with something else like SRP.
I knew this would end up not being simple.
Had a feeling poorboys may not let the fk1000p adhere very well. Resulting in reduced durability.
I rather enjoy waxing my cars but once every 3 months is enough. Will the black hole and fk give me 3 months of summer shine??? Don't really want to do it all again in 2 weeks.