Comment: „Good advice. Yet for now I still went the other route: so no container, but no rubber bands either: the straps are metal ones. And there’s a metal plate for underneath.
Both sides are protected by silicon pads. On Digital Foundry and Amazon I’ve seen there are silicon pads in at least some containers too, maybe just the more expensive ones. I don’t know exactly.
Obviously, there are a lot of different solutions out there. This is the one I ordered: https://www.aliexpress.com/i/4001327062816.html
If I feel uncomfortable with it – or it won’t fit at all -, I can send it back easily. Curiously, I did not get a single small container on the places I usually buy: for example on Amazon. No chance.
All look quite big and have four screws on the side: not only the height of the slot may be a problem there.“