Not an answer to OP's question, but an anecdote that may be of relevance:
I was setting up a road bike, 34/50 up front, 11/32 in the rear, with an appropriate rear derailleur. I had a few used chains with acceptable stretch in the bin, and I brought them out, cleaned them up, etc, and hoped there would be a properly sized one in the bunch.
I took one chain and sized using small/small and experienced just what the OP did - the last cog (32t) simply won't clear and if I forced it I felt like it could have broken something. I added links but it made the small/small feel unacceptable. I went back and forth a couple times, including making b-screw adjustments, and was stumped.
Then, I just so happened to grab another one of my used chains, and found that it matched the correctly-sized length. I put it on, made no additional adjustments to the RD, and everything just worked as one would expect. I then switched back to the first chain and again was having the same problem of not being able to get on the 32t.
Needless to say, I went back to the chain that worked and called it a day. Not sure if the links were too stiff, or the plates shaped slightly differently, or what. If anything, the problematic chain had the less visible wear of the two. Both were Shimano, one was an Ultegra, the other was either an older Ultegra or Dura Ace.
Last edited by tFUnK; 09-20-22 at 12:53 PM.