MIP 3 - Linear EVM memory cost

MIPs
3
  1. Can we expand discussion with EIP-7686 and EIP-7923 in the Rationale section, i.e. why is MIP-3 chosen over them? (my understanding is that EIP-7686 would combine unfavorably with Monad’s “charge-gas-limit” rule, what about the paging from EIP-7923?)
  2. Similar to EIP-7923, behavior of MSIZE after the activation should be confirmed (esp. given the lack of rounding to word in memory limit calculation.) In other words - would MSIZE return limit or limit - 1byte in the case mentioned in (2.)?