Hello,
Just to add a different approach to this dilemma, I ordered from Amazon 1 1/2" long x 3/8" diameter thread (regular not fine thread) stainless steel socket head cap screws (Allen screws) plus a box of 100 stainless steel 3/8" washers and used the washers to space the rotisserie mount 1/2" further out from the smoker.
The socket head cap screws that come with the Komodo Kamado are 1" long. The 1 1/2 length bolts allow you to adjust the motor mount further out from the smoker. I found 2" long bolts too long.
If you can't find stainless steel socket head cap screws then you can get galvanized or stainless steel hex head bolts and washers at any Lowe's/Home Depot. Again, 3/8" thread x 1 1/2" length.
This way you don't have to grind down and thereby ruin the shaft for future motor adaptions. You use washers to obtain different spacing to fit any rotisserie motor regardless of the depth of the motor's shaft opening.
Hope that helps.