It seems like Legendary Tooltips is unable to correctly get the rarity of items displayed on the EMI, causing it to display as "common rarity" style.

Inventory:

EMI:

i think this is related to: #256

From my own experience, it seems that the borders added by the mod bug with EMI, but not the borders added by Resource Packs, I recommend that you test some, like https://modrinth.com/resourcepack/eclectic-trove-legendary-tooltips

AHilyard/LegendaryTooltips#88
It doesn't look like anyone's gonna fix it :/

I built a very crude mixin that build a ItemStack from the translation key and passes it to Legendary Tooltips, which does get around the bug, but it's not a good solution.
Tooltips.zip

Upon investigation, there is event parameter RenderTooltipEvent.Color event in onTooltipColorEvent.
In EMI's tooltip, event.getItemStack() returns ItemStack.EMPTY, which causes this bug.
So I think this is on EMI's side...

interesting

Was this every fixed or addressed? How would I as a user use that mixin?

you can't just use it. you have to complie it into a mod :/

Is there a compiled mod file? I really want to use emi and Legendary Tooltips together