No MTE and AddressSanitizer are implemented completely differently under the hood and catch different kinds of memory bugs.

MTE tracks provenance of pointers which means it catches bugs where a valid pointer derived from one allocation is used to access another allocation. Provenance is indicated by a fixed number of tags available. So there’s a 7% chance of not detecting an occurrence of a memory bug.

ASan is implemented differently: it adds red zones next to allocations. In theory it could have a false negative if a pointer jumps over the poisoned region. But it works well for stack memory in addition to heap memory. MTE doesn’t protect your stack allocated objects.