I was just wondering, since Magnets tend to affect many electronics, and LEDs and their converters and stuff are electronic devices. I am too scared to try it out myself.
Those that has an inductor in the circuit are affected the most. I don't think it'll ruin the circuit though... and if it does, it'll take a long, looong time.
it can put stress on the circuit yes. I put a strong manget to my ARC AAA once and it dimmed down as it kept the coil from getting a mangetic field as it saturated teh coil. remove the magnet and boom it's back.