In your opinion if you were just looking to farm item level 55 whites, what level would be best to sit at?
I am thinking ~60, maybe 58.

Personally 60-63 based on what the Event mods are for the 3 days it is active. In some cases lower.

This is just my opinion based on only returning, but, I have noticed that Events are a key to Higher Tier drop(s) vs Level.

55. Fastest level to kill mobs and imo same chance as any higher level.

I am not so sure its same chance, might be just unlucky but i normally find more after 58.

It is also the same at lower levels... @ level 8 I can find level 5 (Tier IV) items, so maybe this is an indicator that 3 levels above the Tier level is a key number to finding them, now this also means that "Monster Difficulty" (not sure about base, but since Monster Base difficulty is active, I have noticed higher chances of gaining 7 mods on items than I normally do).

EDIT: I may actually test this out more, so to get more of a quantifiable answer, or somewhat a bit more information to the level req.

This post was edited by izParagonzi on May 6 2020 07:31pm

Off the top of my head if i find one at 55 its generally on an EP

I'm going to start tracking this information for me. Unfortunately, you need to find and keep track of thousands of lvl 55 items before the true nature of the game mechanics are revealed

Without eps(regular mobs) Id say 60+

This post was edited by DOHtrader on May 8 2020 06:47am

Mirror maze drops a lot
So explore 70-120

lvl 45+ maps with lots of + treasure chests. At level 55. with a more treasure chest event active.