We used to use an outboard support when we used timing pulleys
Since we switched to smooth pulley over smooth drum, we no longer use the outboard support.
I think that without it, you might be fine, depending on your motor and what steps you take to make sure that it stays together.
I also noticed that all use timing belts and no outboard support...I think that a heavy drum is a better candidate for this than a beater tho...the drum carries more energy and can dampen a lot of the shock
jmo
btw: which bot(s) are you thinking of removing the support and with which motors?
also, if you are usng an outrunner with a 5mm shaft (for axample) check shaft hardness...it's possible that ifit's soft, you sould exchange it for a 5mm hardened dowel pin...like I do in little Sting