My gigs these days have me changing tunings fairly regularly from standard to 1/2 step down from standard. Usually not more than once a week. Both of my basses seem to tolerate the changes fine with no special adjustments needed to work at the lower tuning. My only slight concern (probably borne out of my penchant for over-thinking something) is the nut slots. Should I be concerned about wearing down the nut slots prematurely from changing tunings up and down? I use round wound strings. The nuts are made of bone and when I change strings (every 4-5 weeks), I use a #2 pencil to "write" pencil graphite down into the slots, something I picked up on a couple of years ago. Will this be sufficient or should I go further and get something like the "nut lubricant" (steady, not going there...) that StewMac sells? Thanx.
In theory you will get some more wear. If the nut is cut well and lubed (as you are doing), I doubt it will make a real difference.
in general i think you will be ok. the graphite does help. if you were so inclined you could look at replacing the nut with something from graphtech. you may perceive a slight tone change with the bone that you have vs. their polymer material. ime, lubes and goops tends to attract abrasive dirt/dust and are not for me.
My number 1 is over 20 years old now and has had many many string changes. The bone nut is original and is still fine. So I believe you need not be concerned. But if you want to plan ahead Put away $7.50 each year for the next 10 years and you'll have enough saved for a new hand carved and fitted bone nut.