Most of the time your issue is a complete non-issue though. Professional gear isn't any more sensitive than, say, standard hifi amps are, on the contrary, mostly the ins and outs are better protected. If you are a professional you should know that. Now, if a modified device never made any problems at the bender's home, you can expect it to be safe as everything else. Every half-experienced bender who knows what he's doing will end up with 100% electrically safe devices.