Conaero, this is an interesting update. Do you have any details on the slave cylinder/Thrust bearing shaft that would be causing it to stick? I just put mine together, and still have the entire set up in the other room until I take the clutch and pressure plate over to get it balanced. I'm using the Hill Engineering TB. While putting it together it seems the TB shaft was very well engineered and very smooth to facilitate sliding when the Hydraulic oil is pressurized there. Another forum member here I think has an SD tool or something similar that runs codes and he seemed to think that if the TB got stuck it would send a fault code and store it if that happened. Do you have any data with collapsed pressure plates that this code has been stored in any of those situations? I mean I get what the forum member was stating because the F1 sensor is literally attached to the TB, when thrust bearing moves the rod magnet moves in the sensor's base. If it got stuck, it does seem that sensor would be in the best position to know it.
On a side note I'm just asking questions to further the research not that I know all the answers. Sometimes it helps people are bouncing things off of you. Now I have to admit I want to ask how a stuck TB would cause a PP to fail? If it's sliding on it's base, and it has catch pins so that thrust bearing can not over extend. If a PP is built correctly, the PP is built to be consistently pushed in the area that the TB contacts, and spring back. So even it was pushed open longer from sticking would it effect it?
Maybe alternatively, now that I wrote the above, I could see maybe one circumstance that it could collapse it. If the bearing got stuck at the base of the TB shaft, or a small distance away from the PP enough times, it might continue to pressurize the slave cylinder until it slams the PP with a significantly harder force. That's a guess though, I'm not sure how much pressure it would have to build to throw it into the PP to collapse one of the tangs. As well the TB is designed not to contact any one of the tangs but all of them at the same time, you can see this in the photos below, in which case they all take the slam as a unit and only the weakest link breaks. The shaft the TB rides on will not allow it to hit the PP side-wards or off-set so as to contact only one piece of the PP:
Here's the TB shaft you were speaking about to the right of this photo: