As for adblock, I had good results after I rebooted by chance. This time AntiX cc » System Adblock launched fine and I choose the first three list; hosts was enlarged to <1 MiB (never showed up on previous live session). Only these third parties did show up
So went on my Arch system to have a look on the journal: Revealed that hostsblock couldn't write the rules and wasn't functioning. First time that happens this year; restarted it and it wrote the 14 MiB hosts.block.
Much less efficient than smaller AntiX's I must say, as 39 direct + 33 indirect third-parties are showing up (only 3 with privacy.trackingprotection.enabled=true
in Firefox though)