I certainly don't advocate using the uncontrolled airspace of a MATZ without being in radio contact with the military airfield in question. I don't think my earlier post said that? I agree it would be madness. Yes, to be fair, the OP was erring on the side of caution which can't be bad.
But - and its a big but - the OP used words like "busting airspace" and "clearance" with respect to a MATZ penetration - neither of which are appropriate and indicated to me a lack of understanding of the nature of a MATZ.
And gliders are not the same as manoeuvring fast jets - by all means give gliding sites a wide berth, but to imply that a MATZ-sized circle round a gliding site is appropriate is mad overkill (except perhaps during the launch and start of a competition task - but these are usually notammed)