A good place to start would be to unhook the wire from the safeties where it connects to the engine for a test and just let it run to see if it fails. I didn't look yours up, though it seems to be an issue with plunger type switches that don't quite get fully actuated.

A common thing on any chipper is the Magneto coil vibrates out of tolerance. Yes the switches can be a problem also.

I would remove the stop wire first. Then check it for spark. Then look at the Magneto coil. If it is a Briggs it should be about .014.

Do not rely on looking at the spark plug to see if it has spark.

I had 3 chippers in the shop this week and all had the coil gap out.

I have the one that came before that model and its usually the lower safety on the front leaf intake or the key on mine. The plastic fork on the front safety is a tight fit and is easily undone and the key is kinda worn so it can go past the start notch.

And to check the safety switch is not Rocket Science. You remove the wire and check for spark. If you have no spark it is in the coil. If you have spark then you get out the ohm meter and trace it out. If you do not have a meter you can check Harbour Freight. They usually give them for free.