I agree, those clunk tanks are easy to work with. And they aren't nearly as finicky about position as the metal ones. I don't seem to need to angle the rear out as much as I do with a wedge since the clunk pickup is pinned in that corner while flying out the last laps. I usually pad it with a piece of a thin beer koozie and zip tie it to a slotted ply plate. Wipe some outdoor polyurethane on the plywood.
I don't even plumb uniflow anymore. I use one vent for pressure or open air, and one for filling. Both of those turn straight up to the roof, wired and soldered together, and are bevel tipped so as not to suck up to the wall.
I posted a diagram of it in one of your previous tank threads
Rusty