Well, I asked the question here because I saw something I couldn't explain. I had four instances of dry yeast (S-04 and Nottingham) direct pitched resulting in low pH levels like I'd never seen before, but only in the first generation, each of those pitches taken out a couple more generations behaved normally. In amongst these, W-34/70 and Windsor did not show this phenomenon. Never seen it with liquid cultures. Maybe I never will be able to explain it. It will be interesting to see if it happens again whenever I next use dry yeast. Being something of a dry yeast noob even after decades of brewing, it really concerned me. But it doesn't seem to be a general problem with dried yeast. I'm keeping the S-04 in the fridge as an emergency backup.
(The only one of these I'd previously used was W-34/70 years ago, and I made starters, just to compare it with the liquid versions. That would be another topic.)