Yes, thank you. Is it not so though that when the excessive pressure happens the EGR opens and the pressure escapes intake -> valve -> exhaust? Would be a convenient way.

Now it depends which pressure is higher - the one in intake to the one in exhaust - in which case the excessive pressure would escape to the exhaust (provided the EGR is not blocked) or the exhaust pressure is always higher to the intake pressure - in which case only gas recirc would take place.

If the latter is correct then disabling EGR would not harm the head because of possible excessive pressure.