Is that the magnetic part that can be removed? We deliberately avoided this design since you never know if it might disappear at some point ;)
Yes, that's the thing I mean. TwistPad is the official name, as I just saw.
I wouldn't know how you could lose it, but it's actually not impossible since it's not permanently connected to the cooktop. However, the magnet is strong enough to keep the TwistPad in place; it doesn't happily slide over the glass (and beyond).
But is that really that relevant in the decision-making?
In my opinion, it's like the question about noises with induction. Yes, they exist, but so what? The advantages far outweigh it, making this side effect irrelevant. Do you want to cook faster and more energy-efficiently or completely silently?
By the way, spare parts cost 50€, just in case.