Max, I know of plenty of MATZs where gliding sites operate close to the boundaries and some MATZs where gliding takes place when normal ops have ceased but I haven't seen non-resident (for want of a better term) gliders routinely penetrating MATZs without prior arrangement or normal clearance.
If they are doing it then they are barking and show very poor airmanship.
I think the real answer to cyclically's problem is the 6 Ps or is it 7?