Seen by the RIPE Atlas probes.
The vast majority of the ISPs which do censor return the localhost address (186.2.163.90 is the real one):
% blaeu-resolve -c FR -r 1000 -q A sci-hub.tw
[] : 12 occurrences
[ERROR: NXDOMAIN] : 2 occurrences
[186.2.163.90] : 235 occurrences
[127.0.0.1] : 112 occurrences
Test #20445233 done at 2019-03-31T18:50:16Z
Apparently, Orange implements the censorship, but not (yet?) Free. SFR is the one returning the empty answer.
No change today:
Still no censorship at Free: