I had a thought about my existing #poudriere deployment.
It has several ports trees, one of which I use for updating FreeBSD ports.
My idea: create a new jail (pkg01), install poudriere there, move that tree into that jail, and do all my FreeBSD ports work over there.
The only downside I see: after I work on a net-mgmt/librenms instance, I usually do a `sudo cp Makefile distinfo /usr/local/poudriere/ports/mylocalcopy/net-mgmt/librenms`, then (for testing) I build and install locally before committing the work.
That step would be one extra copy (scp to the existing jail, then a sudo cp into the ports tree).
I suppose I could ease that then-two-step-process by a nullfs (and read-only) copy of the first ports tree into the new pkg02 jail.
Why a separate jail for poudriere? It just keeps my #FreeBSD work separate from my personal stuff.