The "reach inspiration breakpoint" feature seems to sometimes suggest too low quality materials.
It seems to sometimes select material qualities in such way that there seems to be still a low amount of skill points missing (like 1.6 points) to cover the skill points required for a guaranteed highest quality craft in the case of an "inspiration" proc. In the case(s) where I have seen this it seemed possible to cover that by selecting higher quality materials.

On what version are you? And do you have a recipe+profession example?

Changing math.floor to math.ceil in line

Thank you so much for that! Seems to work :)
Included in 1.8.3+