I'm curious. Sometimes i use my wide lens with my Canon XA10 and sometimes I don't. If I have it off, but have the conversion lens setting set to wide (or vice versa), will that impact my ability to get a sharp focus?

Per the note on page 148 of the manual it may effect speed of autofocus, distance marking on the screen, image stabilization effectiveness, and minimum object distance. Subject to that I would not expect it to effect ability to ultimately achieve accurate focus within the capability of the lenses and adapters in use.

Try run some test on your gear to verify any effects.