Oh no worries at all! Glad it was helpful!
It’s the sudden change in angle of incidence (changing the chord line by rapidly deploying the flaps), combined with the change in CP and the downwash over the stabilator that imparts the nose-down moment in the PA-28. What makes it different from a 172 is, for one, the low wing. The 172, the increased downwash impacts the horizontal stabilizer differently.
But in a PA-28 that’s equipped with a Johnson Bar flap lever, when we pull it to each setting, it’s a large, rapid change. I think there might be a difference if the flaps were deployed more slowly, like with electrically-driven flaps. I should actually try that sometime in level cruise flight. I hypothesize that it would be a bit more like a 172 in that instance (but still different).
Somewhat-related question - I have a Johnson Bar flap lever that I picked up from an airplane parts dealer. I’m trying to fashion it into a sim controller for this very purpose. Is there a variable available that would allow the position of that lever to not actuate a particular flap setting, but to directly affect the instantaneous position of the flaps, correlated to the position of the axis, throughout any intermediary position in their range?
If I remember correctly from my work on the C310, in the flight model, the flaps are parceled to specific settings and are not acting as a fully articulated, independent control surface. If that’s indeed a limitation, it may be time to ask Asobo if they can look at divorcing flaps from the rails (as it were) and make them behave as any other control surface. I mean, at the end of the day, they’re just like big inboard ailerons work in unison, only deflecting down, and lock into certain positions (I suppose the different styles of flaps will play into that as well). But consider hybrids like flaperons, etc. It would be nice to have that kind of flexibility.