In article , "Richard D.
Saam" writes:

Dark matter slowing down at a rate other than observed baryonic contents
does not in itself exclude a baryonic DM character.

True. Optical depth alone does not exclude that dark matter is made of
bricks. Or back issues of the ApJ. But other arguments do. Ditto for
a significant fraction of dark matter being baryonic.

Give this evidence alone,
DM could be a different baryonic size/mass distribution
providing a different lag character.

Sure, but "this evidence alone" is not a good choice when there is other
evidence available.