installing hub motor without ruining dropouts?

have a kona stinky I like. I put the 9c in there but it has maybe .2cm from top of axle gap.

the cromotor I have fits but would ruin the metal. is there really a way to install a hub without opening the dropouts aka making it useless to go back to pedal form or mid drive?

Many small and mid sized motors need a standard 10mm dropout. Higher powered stuff would break at that size though. My cst fits just fine on my Claud. I have known of depth issues though not just width ones. My 10mm flats are on a 12mm axle, so the radius of the threads is not the same as that of a 10mm axle that is perfectly round. The top of a slot might need brushing with a file, but that won't stop a normal wheel going back in.

I looked at often talked of stinky and imagine it has lots of meat on it to play with. Some of them things weigh nearly 20kg!

Just reshape the bottom of the dropout to fit the axle better. Putting back a normal wheel will still fit the same, if you haven't actually made the center of the dropout any deeper.

Good torque arms will prevent any axle movement from wallowing out the drops wider.