Heya @TheGreendalePom
It really depends on the customer and the look that they are after. Tbh I just give it a light sand normally as it’s supposed to be rustic and have character and if I sand it or plain it to much then I may aswell go and buy dressed timber.
With pallet wood there there is always the chance of a splinter here or there but buy giving it a light sand I would say reduces the chances by about 70% and I also oil or varnish it as well which helps stick them down a bit too. Hope that helps
