Something else to think about. The transponder in the fob creates a small magnetic field, to which the ignition switch responds. A bunch of keys next to the fob create their own magnetic field which can interfere with the fob field.
Many cars which still have a key have a transponder in the key, and owners manuals will warn you not to hang a bunch of other keys with the ignition key. Would imagine similar warnings would apply to fob-equipped cars.
As a former Toyota dealer, we had a number of callouts from people whose cars "won"t start."
Not a good idea at all to hang more than one or two other keys with your fob.
