Wheel drive bulkhead mount bracket

I am installing Evolution Wheel Drive on my sailing catamaran. This is a bulkhead mount. I have cut a 2" [censored] in the bulkhead for the drive motor to pass thru. My question is "Is the bracket that goes in slot 1 or slot 2 necessary?" On a pedastal mount, the drive motor would be in mid air and the pedastal bracket will hold the wheel assembly stationary. On my bulkhead mount, the [censored] for the drive motor would be doing the same job. Would eliminating the bracket place too much stress on the motor?
Thank you.
Mark Zorn