Not sure that this a good or bad idea. Something needs to open to relief the pressure. If not, the pressure will look for the next weakest point and maybe do some more severe damage. In Austria/Germany they install a device in the chimney near the boiler that has an "explosion cover" It is typically integrated in the barometric damper T. The explosion cover is spring loaded. So it releases the pressure and then closes again. This all happens in a fraction of a second. I will see that I can find a picture. Also, in Europe (Italy), many pellet boilers have a similar spring loaded cover integrated in the boiler body to prevent this when pellet ignition failed and lots of wood gas is present in the fire box and suddenly ignites.