Smart Reach Bed Phone Pocket-Lavender, Secures Between Fitted Sheets with Special 2 Piece Magnet

Would it work on a metal loft or would my phone weigh it down

would this hold a remote control for a TV or an adjustable bed, which is much thicker than a cell phone?

Where can I get a replacement magnet? Mine seems to have disappeared while changing my bedsheets recently.

does any part of the metal have sharp corners or edges? Id like to use it on an air mattress.