I would Confrom your seq. --- Then consolidate it. (I believe you can also consolidate when you import the AAF) -- and then cache the sequence.
Your export time seesm about right. I can export a :30 sec spot in about 2 mins. at DNxHD145. (Quicktime)
Not sure if the export will be any faster with the cache, but since it's frames on your framestore and not exporting via SAN or wherever your original media is. If it's all on the same storage... then I doubt you will see an speed increase in Export and you would have wasted time on doing the cache.
Adjusting the proiority setting in backburner won't do anything as they are just values that the Smoke what process to focus on when it has several background tasks to do.
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