So would I. Beginning with Catalina, our imaging & deployment process requires systems being in ABM. We're loaded with hardware that is fully capable of running Big Sur and even Monterey, but which is stuck on Mojave because not being in ABM means we can't image anything newer onto them. Technically, you may have other options. Apple can't enroll hardware after the fact, and neither (until now) can you, but the vendor who sold to you can. Only one vendor has ever responded when I asked them about this, but I did find one willing to do this. The catch was that they can't add single machines, they can only add entire orders as a block, which they went ahead and did, which enrolled hardware we no longer owned, which we then had to go in and manually unenroll. But if you know where all your hardware is by serial number and are prepared to deal with that, you might want to talk to your sales rep.

Your notes say that only Apple Silicon and Intel T2 hardware can be enrolled in ABM/ASM using Apple Configurator for iPhone, but the actual transcript says nothing beyond "can assign Mac computers running macOS Monterey." While I understand why you'd need Apple Silicon or a T2 for the Revive and Restore functions, do you need them just to enroll?