sanding before fixing creaks (read slight movement)

I've got the sanders coming around tomorrow but probably aren't totally ready for them. Mainly I wanted to fix all movement of floor boards from underneath - there's a bit of creaking going on, but aren't really going to have time. I know it's a bit of a "how long is a piece of string" question but am I likely to notice any uneveness after sanding if I don't. As it is the boards are old cypress and have a number of gaps here and there anyway so it's going to have a rustic feel as it is.

At a minimum I'm going to hold of oil/waxing the floors until I do that (and a couple of other things) - and yes I know I'm going to have to be extra careful about marking stairs/floor until I do.