Documentation: demix=null still uses demix_sources

I found the documentation of demix a bit ambiguous regarding the automatic determination.

demix: if true force demixing using all sources of 'demix_sources', if false do not demix (default: null, automatically determines sources to be demixed according to min_separation)

I interpreted the description of null as meaning it will ignore demix_sources and automatically check which A-Team sources are close enough to need demixing, but it turns out it only checks sources included in demix_sources. I was reducing a set that has TauA extremely close, but had the wrong demix_sources set. This resulted in no demixing regardless of it being set to null.

Perhaps the documentation can be expanded a bit to emphasize to the user that demix_sources is still used, even in the automatic case?