The ordinals experiment has clearly shown that you can't stop non-transfer uses within the existing consensus rules.
We have been stopping them successfully before Taproot by making them non-standard which discourages such spam. Otherwise you could create a scriptpub with an arbitrary input that is a little smaller than 1 MB.
as for other for instances. multisig/p2sh. if needing a 15-of-15 then have 15x80 limit
instead of the lame softrule of "go ahead take 3.98mb, we dont care"
A Schnorr signature is 64 bytes and with the public key it becomes 96 bytes. 80 byte limit is not enough for any type of Taproot witness. You also can't use OP_CHECKMULTISIG in Taproot scripts, OP_CHEKSIGADD is used so the 15-of-15 size is not the same as before needing all 15 keys and signatures.