Pretty well, I did the first day and a bit on my old BT014s, they were tearing up a bit at 31/31, but they only really lost their shape on the second day. Then I stuck on some new Diablo Corsas (180 rear...what a difference, even I felt it). Day and a half on those was no problem, didn't tear up or wear much at all. At my sedate speeds, I reckon a new set of tyres would have lasted me the three days (or even the four you're doing!) , no problems...But you're going to pushing on a bit more...
Oh...one thing I should say, with the open pitlane, I was going out, doing short sessions (10 - 15 mins) then coming back in again, so the wear probably wasn't as bad as if I was doing fewer, longer sessions.
Well met the motofreight guy today, and bikes on its way.
Said hed got to go up to Glasgee to get 16 bike! They are transporting a total of 90 all together, so take off 5-10 for instructors leave around 25-30 in a group!