For example, Light of the Dawnstar doesn't show any benefit from scaling.
only 9% from Light of the Dawnstar with no scaling
light of the dawnstar scales with religion at like 5 +.25% per religion and it rounds. I think I've gotten up to 11% with xoti putting everything into religion (as recently as 4.1.1). it's very slow scaling.
re: mirrorback, if you have console enabled, can you create/equip a Pearlescent Rhomboid Helstone https://pillarsofete...omboid Helstone and see if it shows up in character screen? That definitely works with spell reflect (I had Eder use it to get enemy mages to kill themselves with minoletta's sigil a few patches ago), so if it doesn't show up in character screen then the fact that Mirrorback doesn't show doesn't mean it doesn't work.
also, not every item shows its effect on the character screen, especially conditional ones. for gambeson, the best way to test would be to just sit there with aloth or a mage spamming missiles at someone equipping the gambeson. that'll give you a quick answer whether or not it works (if you reflect a spell with it, it should attribute the effect to the item itself).
funnily enough, i had a very similar set up to you in my last run (xoti with light of the dawnstar, spell resistance, mirrorback, and then gambeson until i replaced it with weyc). i'd be interested to know if any of that is actually broken.
Edited by thelee, 12 February 2019 - 10:18 AM.