Best tier for blight maps?

First of all, apologies if I'm posting in the wrong section. I'm not confident this is the right section for this but I couldn't find a better one. Anyways, I've been doing blight maps lately since I find them challenging and somewhat rewarding but I can't decide on which tiers I should stick with. Both high tier and low tier maps seem to give a reasonable amount of rewards but I can't quite decide on what tier I should farm. I like to use teal/crimson oil on them to increase the rewards and even made a spreadsheet to calculate the average profit from each map. To those that spend a reasonable amount of time on blight maps, on which tier should I be focusing on? Replies are very much appreciated

kinda 2 month necro but ive found tier 11 to be the sweet spot for me. 3X tealing them, and just running them i don't have any hard data to support it but they are comfortable to run and arent to hard, they have seems to drop better stuff than lower tiers without being outrageously expensive. im tired sorry for grammar and stuff. hope it helps

Blighted maps are extremely cheap this league. I'd recommend running the highest tier you can handle consistantly without a chance of failing it.

Some rewards like golden oils or shaper/elder fragments are only available in T14+ so I'd probably only run those tiers.