Spacer for Encoder on Baron platform + drilled holes

I would like tp point out that I am having the exact same problem as reported here [url=http://www.dfrobot.com/forum/index.php?topic=817.0.]http://www.dfrobot.com/forum/index.php?topic=817.0.[/url] In order to have proper spacing, I had to slide in the motor, put in extra washer, lock washer and nut from the provided hardware, then the spacer and the encoder.

While I am here, is it just me or in spite of the many whole drilled already, none of them allows the proper seating of an Arduino Uno without drilling at least one extra whole