Wow, someone missed the point of the question…
We have done white label in our other business – Vape Liquid.
It does add more work as far as setting up a label in your system. many places charge a fee to set up this. We used customer submitted artwork then build a label for their brand. If you have someone that is good at making labels, it will not take much time at all.
All in all, not a lot of extra work. Just label set up time. But makes for longer lasting customers in many cases.
Your mileage may very, but we had pretty good results doing it for our customers.