This scheme sounds exactly like old state of affairs under the Classic Mac OS back during the 68k era. Macs back then had no MMU, so the OS provided a surrogat

This scheme sounds exactly like old state of affairs under the Classic Mac OS back during the 68k era. Macs back then had no MMU, so the OS provided a surrogate "Memory Manager" that abstracted away pointers into handles, which could be marked as purgable, required checking if the memory "moved" due to heap compaction, and so on. As clever as it was at the time (the original Mac fit in 128K, not M, K!), it just proved too limiting and error prone and held down the platform until it was partly jettisoned by OS 8, and fixed for good by OS X.