Pretty much all of the above.
First, you have to reach max ias.
For max ias with pb and zeal but without fana you'll need 72ias. 30ias is covered by azure itself. 40 can be gained through highlords and loh. So you would still miss 2ias. You could gain that with a shael or 15ias jwl in weapon but imo that would be a waste of the socket slot. Better use a 15ias jwl in one other possible slot or nos coil.
But if there is absolutely no possibility to reach 72ias without the shael or 15ias jwl, than use it before everything else. If you don't need the additional ias in your azure, I would ber it because your other equipment will be likely towards lightdamage already (griffon etc). If dual dream and self conviction it depends on areas you run.
For max ias with pb, zeal and fana (lvl20) you'll need 11ias and you are already covered by the ias azure gives you. If you have self fana, this is most likely your only free socket and it heavily depends on which areas you are running. For farming lvl85 areas you are most likely better off with a rbf but if you are running only bosses without killing anything else, ber would be better.
For max ias with pb, zeal and lower fana lvls from merc faith or necro/barb with beast (i.e. lvl9 or lvl12-15) you are covered as well by azure (fana lvl9 needs 19ias). With this setup you could be running dual dream and self conviction as well as self holy shock, so no advice here without knowing your full setup/preferred area.