A full length mudguard does not serve much purpose to you, but it is a courtesy to other riders who may be trailing behind you: it keeps you from spraying water and debris high into the air behind you.
You could just stand the bicycle on the mudguard when inside that small lift. You're assuming that the mudguard will be damaged, but perhaps that assumption is wrong.
If you stand the bicycle on the mudguard, the mudguard will probably bend until it makes contact with the wheel, and that will cause the mudguard's supporting rods to also bend. This is not good, but perhaps the situation can be remedied by inserting some spacers between the mudguard and tire, such as eraser rubbers.
The rubber pieces will transfer the force from the contact area where the mudguard rests on the floor directly to the tire, relieving the mudguard and its hardware from stress.
If you're worried about scratching the mudguard, you can put some tape on the contact area. (Hmm, will there be a rear reflector on your mudguard?) Or just carry some small cloth for that occasion. You can wrap the erasers in it when it's not in use.
Incidentally, that rear reflector is another good reason for a full-length rear mudguard. It's a good spot for it.