After MONTHS of BACKBREAKING LABOUR I have succeeded in shifting the mantle icons SIX PIXELS DOWN.
(I'd assumed it was going to be more work than that so procrastinated in giving a first look at the issue, soz)

When under the effect of white fireplaces or Soul of the Lost, mantle icons will now overlap your hearts instead of appearing after them. This is what the vanilla game does.

Removed manual fix of Tainted Forgotten double Dogma, since that got fixed in the base game.
Now supports picking up mantles with your Strawman. Why would you do that? I'm not sure.
Took the advice of commenter Nioffe and made it compatible with mods that edit heart sprites. It's even compatible with mods that edit the sprit of the mantle, though it'll probably clash with the custom mantle sprites this mod adds.

Tainted Forgotten no longer gets two Dogma shields in the beast fight. Fix your game, Kilburn!
They still get the other benefits of two Dogma items though, such as increased damage.

Exiting Lost state (through Soul of the Lost or white fireplace) will no longer give you a one-use mantle charge.

Fixed broken hearts ruining mantle placement.
Fixed player 2 mantles only being aligned properly when using the exact same game resolution as I was when testing it (haha whoops).
Fixed player 2 mantles not being rendered mirrored.
Did some heavy reworking of existing code, which should hopefully remove some bugs I didn't know existed and definitely not add a bunch more bugs I don't know exist.

Known issues remaining: mantles can render above your remaining lives which can make them hard to see; mantles render above everything including the pause screen and the tv-turning-off effect from killing Dogma. Both of these are basically unfixable without causing more issues than they resolve, so I'm just going to hope nobody complains about them.

Fixed a bug with losing wooden cross messing with your holy card.

Added vanilla-friendly mode, which doesn't change gameplay mechanics at all. Enable it at your local MCM (terms and conditions apply).

Initial upload