HELP - "Svalinn" unique shield AND "More than skill" stack luck?

I'm wondering how this mechanic works. In theory, luck doesn't stack. So even if I have both, only 1 extra dice roll will apply, right?

But what happens with unlucky items like "The Iron Fortress"? one luck instance cancels the iron fortress unlucky roll, and the extra luck gives me another roll?

Didn't find much info about how multiple instances of luck work.

I want to know, idk either

Lucky and unlucky will cancel each other out.

I'm guessing that if the lucky mechanic doesn't stack multiple rolls (unlucky, lucky, lucky) will be the same as (unlucky, lucky) result in null. Mathematically it would be an order of operation question. So it depends how it is programmed, it may be instead as suggested in question that the count of each, ie. -1 +1 +1 results in +1, but it seems more likely to be the null case to me. There are also other possibilities. I'm only guessing based on information in this thread.

(Chest, Shield, Glad ascendancy). I think chest will nullify both, not just one. Still only guessing.

from the wiki:

"Lucky and Unlucky modifiers affecting the same stat or mechanic will cancel each other out"