So, what is the difference from a Monero user who also relies on a node to do this for them?

Monero users *can't* personally verify other transactions themselves. Bitcoiners can, but *don't* (infeasible to do every ten minutes + ~1 billion txs that already exist). ***In practice, both rely on their nodes to verify for them. They're both vulnerable to being unaware of implementation bugs in software.***

I would really like your answer to this as I've never had a good response from anyone.

I don't know why you assume this would be caught fast. It wouldn't even necessarily be detectable by nodes. There was already a supply inflation bug in 2018 that would've gone unnoticed by nodes. That was only avoided because of a single anon reporting it before it was exploited.

Ok, but option 1 means a hard fork (your desire for ossification can never truly happen if this is always on the table) and you just potentially fucked over millions of innocent Bitcoin users (especially if Bitcoin grows in adoption) who gave away real goods and services. You've now Thanos'd their payments. That would surely be catastrophic for confidence in Bitcoin. Hence no good solution.