The create mixing recipe for tome of alkahestry doesn't check for tome of alkahestry durability being positive. As in, the tome's durability can go into the negative numbers and you simply duplicate the material.
Forge, 1.20.1
Reliquary version: 2.0.36.1199
Create version: 0.5.1f
Searched through open and closed issues to see whether this was reported.