Most Warmoth necks are playable as they are received and do not require additional fret leveling. If you desire extremely low action or some other specialized feel, you may wish to consider additional fret work. Because wood moves with changes in temperature and humidity, fine fret work is best done after the neck has adjusted to these changes, and been strung up to pitch for several days. For this reason, Warmoth leaves this fine tuning to the end user.
While stainless steel and gold fretwire are harder material than nickel/silver, the same fret leveling/dress techniques can still be used. They take longer to dress, but these harder frets will last much longer than comparable sized nickel/silver frets.
On necks with Maple fretboards, where the finish covers the fretboard, the finish is sprayed directly over the frets. This finish will wear off quickly with use, or it can be scraped off quite easily. A fret leveling operation will also take it off.