Some things:

First, Blåhaj Lemmy is pretty friendly from my experience, so I struggle to see how it would be an extremist instance. Also another instance in the block list, Ibbit, if anything, seems to be aligned with the political vision the dev's block list implies, so I don't see why it's included either.

Second, a problem I have with Piefed too, I don't like the idea of a central power deciding what is good and what is not to the individuals or even for administration. Lemmy has an instance-blocking feature on the individual user's settings, so let him/her be mature and choose who he/she walks with. And if administration thinks a given instance isn't good for the experience intended in their own instance, that's for them to decide and for the users to decide if the administration's choice was good or not, not for an easy-to-miss setting to.

Third and similarly, for the other domains blocked, use Ublock Origin/Violentmonkey to hide posts with them, ask Dessalines to add a per-user domain block feature similar to Mastodon and Mbin's, or whatever. Again decision should be in the hands of the users and administration.