"filtering the based reaction fluid prior to extracting the freebase meth?"
Yes, thank you, that's what I meant. Especially before a second pull. SWIP has found that clearing away the particles that tend to accumulate after basing allows for better/more complete pulls. (Not that this is likely to be news to you.) SWIP has even been known to filter both the based post reaction fluid plus nonpolar solvent, on it's way into the sep funnel, prior to gassing, if it contains solids. He thinks it helps increase yeilds.
PP