I just wanted t to get some feedback on the issue above. My experience with building wheels is that nipple in carbon rims seem to set over time (due to compressing the carbon at the nipple seat?) requiring retensioning, up to running out of thread on the spokes (that happened to me once even despite nipple washers). My further concern is little cracks on the rim spoke hole, as I encountered on a set of older Zipp carbon wheels (not self build).
So nipple washers should help distributing the load (I have used the ones from Sapim in various sizes) - do they?
Yes, I set and measure spoke tension with a spoke tension gauge.
Thanks for any feedback