>>96520001
Huh? That's actually pretty interesting because that's NOT how I remembered the B/X rule to work.

I always interpreted it the way OSE does, that is there's two Encumbrance systems (not counting the default "ignore encumbrance" one), and the DM picks one of the two systems and ignores the other one completely:
https://oldschoolessentials.necroticgnome.com/srd/index.php/Time,_Weight,_Movement#Encumbrance_.28Optional_Rule.29

However, what you're telling me is that you do both calculations and apply the WORSE of the two Encumbrance movement rates.

So I went back to Moldvay to check the original rules again, and while I think it's not crystal clear but rather ambiguous, your interpretation is both legitimate AND the better one because, textual analysis aside, it's a better rule at the end of the day.
Picrel

The more you know! Carry on.