For the basics we need to GetPawnWeight() or GetActor().Weight on the pawn, or something similar, to determine our character’s weight.
Then We need as many items as we have pressure plates that close doors too quickly.
I have three doors without the main entry, but only two of them will likely pose a challenge. So I want two items that are assigned the weight-assessing formula – GetPawnWeight(), … – or multiple items that cumulatively make up those weights.
Since I have three pressure plates, I think limiting the game to two objects makes sense. Then there can be a little bit of a backtracking strategy but also a challenge in deciding what plate to activate with the object.
Here my floor plan with escape rout:
I will want enough weight spread across the objects (maybe an odd number to extend the puzzle aspect?) to activate Plate 2 and Plate 3 at the same time, and enable the escape.
Door 5 with a Plate 4 right in front of it will solve the problem of using Door 1 without grabbing an object.
Plate 1 and Plate 2 have telegraphing lights to indicate importance to the spot of the plates