Both Thermal Expansion and Mekanism have sawdust as a byproduct of processing wood in their versions of the sawmill, but Mekanism's version is oredict'd as "pulpWood" while TE's is listed as "dustWood".
So here's a small suggestion, why not use both versions at the same time, or reach an agreement as to which version use? Although I believe I've seen "pulpWood" being used more often.

I opened this "issue" on TE's github as well.

Added for v7.1.