I have a window seat with shallow storage underneath (100mm deep storage, 560mm deep lid of 18mm birch ply). I've not had any luck finding soft close lid stays. The piston ones I've tried are soft close until 45 degrees and then they slam shut because I can't put the piston deep enough to get a relatively decent angle. The hinged stays (hafele duo flap) require about 180mm of clearance so I can't use those.
Due to the weight of the lid (5-6kg), I can't rely on soft close hinges. Poorly sketched diagram below:
Anything else I can try to keep small fingers safe?!