To clarify: it's my sister's address in Massachusetts. It's my billing address for credit cards, bank, etc. I have noticed that all of the courier companies seem to be based in the same part of FL, either Doral or Miami, and within blocks of each other, same zip code. So to use that as a residence address would certainly set off red flags, if only because I'm reasonably sure that zip code is not zoned for residential use. (Remember zoning? Sigh.)
As far as using the physical address of the courier svc here is concerned, I tried to get a new passport sent to their offices (I use EPS in Sosua on Pedro Clisante) because I was afraid I might not be home when the passport arrived, and let's just say it didn't fly with the US Embassy.