One concern I'd have is that those small magnets seem to really prone to corrosion. We use similar small magnets for trim pieces on tanks that we have to remove for maintenance. Any that get exposure to humidity start to rust and swell pretty quickly. My guess is that,with the conditions seen riding, they would need pretty frequent checks and maintenance. If they start to swell in the pedal, they'll likely be a hassle to remove, and leave behind a bunch of small magnetic filings that are a pain to clean. We coated all of our service mags in epoxy because of how quick they deteriorated.