There are plenty of carburetors that are bolted directly to the intake that don't have issues with boiling the fuel. So I don't think that's the primary concern here.
But there are also double-thick gaskets with insulators sandwiched in-between that can be substituted to a certain extent.
The primary concerns are gasket surface matching, and gasket surface matching!;D
I bet there are plenty of carbs out there that no longer, or perhaps never did, match the mating surface on the intake.
With several different Ford style carburetor gaskets to choose from, it's possible that one of them might be a good match to both the carb and the intake surface.
You can probably drill and tap your own hole for a PCV fitting I would think. Some manifolds might not lend themselves as well to that, but I think most have some way or another to access the common plenum area.
Then again, with an intake that's got two or four discrete holes, the spacer was the manufacturer's answer to a common plenum.
It could still be done with just the intake, but it would require some special creativity with some.
Maybe one of the semi-common 2bbl aftermarket spacers made for performance applications might make a good "adapter" and fit between. Then you'd have an easier part to modify to pull vacuum from.
Trans Dapt 2134 and 2135 open spacers could work maybe?
https://www.summitracing.com/search...t&sortorder=Ascending&N=4294916476+4294863980
Not sure what the diff is. Didn't read the details.
But check some of them out and see if they are compatible with your intake and carb. The wide surface flange area makes compatibility more likely.
Paul