The major issue I see with *direct* adoption of the Vampire is that the "Apollo" CPU core they've designed has no MMU support. In theory that might not *strictly*, 100%, be a deal breaker for running MacOS, it could be possible with semi-minimal effort to graft on minimal Macintosh-compatible "HMMU" mapper support, thereby converting any originally-68030-equipped Mac fitted with your accelerator into the equivalent of an extremely highly-clocked 68020-with-no-MMU original Macintosh II or LC. It would rule out using virtual memory or running anything like NetBSD or A/UX on your upgraded machine, however, and there may be ROM and OS compatibility issues that would have to be worked out. (I'll revisit that below.)
Another thing to note is that as of yet all their "it actually exists" hardware targets 68000 machines. They don't actually have a version for 68030-based Amigas. (They're currently working on one for the Amiga 1200, which uses an odd-duck of a CPU, the 680EC20, which can kind of be thought of as a 68000 with a 32 bit data bus but retaining the 24 bit address bus, but even that one seems to be sort of in vapor-ware land.) Therefore an upgrade for an SE/30 or better Mac would be breaking new ground for the hardware. The SE is of course a 68000, so in theory at least that's less of a stretch for the hardware, but then we get back to software problems: The SE is strictly a 24 bit addressing machine and lacks any support for the "32 bit clean" memory model needed to use more than, best possible case, maybe 12MB of RAM. (Strictly speaking, because of peripheral mapping issues the SE is limited to 4MB of RAM unless you shuffle I/O around. And of course it's also missing things like Color Quickdraw, which is a prerequisite for any 32 bit software.) To make full use of something like a Vampire in a plain SE I think you'd pretty much have to cook up a hybrid ROM and implement a memory mapper that would essentially turn an SE into, logically, something like a cross between a Mac Classic II, an LC, and an SE/30.
(IE, map whatever RAM is on the card into a linear space for main memory, use the RAM on the main board *only* as video RAM for the built-in display, and shove the rest of the I/O on the board up to the top of the memory map, modifying the drivers appropriately. That last part is essentially what 32 bit Macs do when they're switched from 24 to 32 bit addressing, the deal here is you'll have to do it with the custom memory mapper you add and, again, fake out MacOS into accepting it's running on something that doesn't really match any real world Mac. Considering the success of emulators like BasiliskII which themselves don't really much resemble any real Macintosh it's probably very doable, but it'll require some pretty low-level hackery to pull it off.)