I have read from a guide on the Kaiser's Bunker website that the mere weight of the liner is enough to eventually damage it. The website suggested cutting a piece of foam to support the liner and prevent damage.
Is it actually being done? It seems to me that this would be pretty hard to do since making it just a bit smaller wouldn't do anything but prevent ventilation, and making it just a bit too tall would actually apply additionnal stress to the liner thus damaging it further.
The article can be found by clicking here. Since it seems impossible to directly link to the correct page (which can be found under the Display menu), here is a screenshot of it :
Is it really worth it? Do you guys actually do it?