I did a Kahimir Drift lair revie yesterday with 3 tags. Only thing I noticed different is I got my first HP-Bayld ever. I've only gotten t1-t4 visages mostly from the colonization revies there.
I also noticed this as well. You're right. I never got H-P Bayld until last night in Marjami Ravine. 1 out of 5 I'd say. Usually I solo them so I get at least 3 evaluations every time.
Does more evaluations usually mean 'better' drops?