I've never brewed and am in the process of securing WVO sources. I've got a few small-volume sources lined up but they differ in the feedstock -- one is canola, one is cottonseed, another is to be determined. Am I creating any problems by mixing them in a single batch, or is it better to keep them segregated?
Thanks.

There's no real need to segregate them. They all contain essentially the same fatty acids anyway, just in different proportions.

The only reason you might want to keep them separate would be to affect the gel point of the final product. Say for instance you might want to keep the canola (or cottonseed-I don't know it's gel point) oil separate to make bio for winter use and use the other oils for summer.