The issue is in the recipe recognition system for Precision Sawmill. There is a single wooden item with ID 4955, and that is GregTech's wooden crate. However, Greg uses the same ID (with different MetaData) for all his plates, dusts, foils, screws,... mostly metallic stuff. All of these get processed the same way the wooden crate does (naturally, turning dusts into sticks is hardly an exploit in terms of usability, but you know, it's weird).

Mekanism version: 7.1.1.102 @ Forge build 1208
Machine: Precision Sawmill
Expected input: GregTech: Empty Crate (4955:32404) (wooden material)
Actual input: GregTech: 4955:* item range (including dusts, plates, screws, foils, etc.)
NEI handler: Lithium Dust (4955:2006) displayed for the whole 4955:* range; checking usages of other 4955:* items returns the Lithium Precision Sawmill recipe
Output: 6 sticks + 25% sawdust (valid for all 4955:* items)
Suggestion: Either hard-code remove the Precision Sawmill recipe for item 4955, or force only 4955:32404 to be accepted for input

This is a bug on GregTech's end - we don't add any recipe integration for other wooden things ourselves.

Could it be because all "plankWood" oredicts that have metadata are registered by our recipe handler with the OreDict Wildcard metadata value?