The PT ignition switch is a generic lawnmower item. It probably cost about $2.98 I'm astounded that mine has lasted this long. When it quits, I will replace it with a DPST toggle and a pushbutton as JJ suggests.
Relocating to the ROPS is fine as long as it doesn't involve making big holes. The ROPS tubing on the 425 is just schedule 40 water pipe, not some kind of fancy chromoly unobtanium tubing. You can see by looking at it that the pipe is plenty big and strong enough to handle a simple rollover of a 1300lb machine. If you flip it off a 300 ft cliff at 80mph, you're on your own. There's plenty of margin to accommodate small screw holes for a switch bracket. You can avoid any structural concern by mounting the switch bracket to the canopy instead of the tubing.
I won't relocate mine to the ROPS. I'll just drill another hole in the control panel and use good switches.