I would agree completely with utilizing the Tier 0 block list at the minimum. If things got bad, and users were being harassed, then going further would be justifiable to me. I prioritize safe communities over free speech, if a trade-off has to be made.
Also, I believe the research on Mastodon CSAM that made all that noise last week, pointed out that utilizing the Tier 0 block list would have filtered out like ~80% of the stuff they found