No sorry, I do not know any API like this and I guess this is not given and handled on server side, same like the effect sparkles shown.
If there is no buff you can see on your character if you press C and scroll down, there is no way to tarck it.
You could check if this addon is able to track it, but maybe it only supports monster sets and proc sets (where this somehow is a proc
):
https://www.esoui.com/downloads/info...cSetTimer.html
Or maybe he knows a way to add it + an indicator for you which is better visible. But I also think this is relying on the buffs shown on your char.
As there is no IsCrouching as I said all one could maybe do is create a workaround addon which does the following:
Use the event stealth_state_changed and check if the state is something like "could be crouching"
There are some states like "hidden but detected soon", "hidden", "hiding" etc. which say in total: "You are crouching". It's not very accurate but best one could use.
Then check if the set is worn, and 5 pieces are active.
And then show some visual indicator icon on screen, or maybe also check if not full health/stam/magicka and if there incoming regularly ticks of health/stam/magicka (hopefully at the same time so one could exclude other heals, as I guess the incoming values depend on the quality of the set items worn and other parameters? Or are they always fixed the same values like 670?
I'm writign this here for other devs as I'm not going to work on this. I got way to many addons already to maintain, but perhaps someone is willing to use the info and create such a helper addon for you.