I would check to see if it's been de-fatted. The fat in the nuts can mess with head retention and other stuff. Lots of nut meals can be had with fat removed, so that would be handy. I think pecan extracts are pretty good for the most part too, and they contain no oil.
If you're using nuts or nut meal, I would sanitize them in some vodka overnight, which will create its own sort of extract, and then dump in everything (nuts and vodka) into your fermenter AFTER fermentation has completed. You can do this in primary, or secondary if you prefer.
I can't be arsed to keep up this list of what's in the fermenters, but hey, check out the cool brewery I own!
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