When crafting slime boots, they do not have any of the modifiers and only 1 durablility, they also stop all momentum while bouncing with a slime sling.

This is fixed in the latest version of Tinkers Construct.

I have tried to update tinkers and mantle in my C:A&B v1.3 instance, and I haven't had any problems. But I am not in any way affiliated with the pack developers, so whatever you do, make backups before you upgrade anything.

If you upgrade the slime boots or slime skulls (same issue) with anything they seem to be fixed.
I tend to throw a slotless expansion on it like a music disk for harmonious +1 upgrade or a diamond for extra stats.

If you upgrade the slime boots or slime skulls (same issue) with anything they seem to be fixed. I tend to throw a slotless expansion on it like a music disk for harmonious +1 upgrade or a diamond for extra stats.

Doesn't seem to be fixed as it doesn't get it's base upgrade points (it has 5) and one ability point, it just gets 1 upgrade point from the harmonious, but it does get the durability and normal modifiers it has back