Before choosing a shower bench, decide whether someone will sit on it. This sounds obvious. Many drawings contain a large tiled rectangle whose eventual job is holding bottles.
Make the seated position real
Mock up the proposed seat on dry ground with a stable chair or suitable support. Check comfortable reach to the controls, hand shower, and products. Draw the shower door and the space in front of your knees. A seat positioned beyond easy reach of the water controls misses much of its purpose.
For someone with a mobility need, involve an appropriate accessibility professional in the complete layout. A seat by itself does not establish safe transfers, grip, or access.
Compare the space both ways
A permanent bench can integrate neatly with the tile composition and be ready without adjustment. A folding seat can release floor area, but only after you account for its projection when stowed and the hand movement required to operate it.
Schluter’s bench guidance describes integrated waterproofing at bench connections. For a folding product, obtain that manufacturer’s mounting, capacity, and waterproofing requirements before the walls close. Tile and a reassuring screw do not establish structural support.
Do not buy a seat to solve a shelf problem
Our preference is to choose the seat around a real user and the storage around actual bottles. If nobody wants to sit, leave the standing area useful and design suitable storage separately. If sitting matters, treat the position and support as the main decision, with the finish following afterwards.