So.

One star, 97 difficulty, 40 durability synths.

Twinthread for WVR.
Spruce Lumber for CRP.

Same danged difficulty.

Can someone explain to me why my CRP, at 359 Craftsmanship, can complete Spruce Lumber in one step with Ingenuity > Careful Synth II (exactly 97 progress), but my WVR who has 361 Craftsmanship cannot? It fails at 93 progress. I'm literally using the same macro, and there's no food or FC buffs involved.