Very long processing time on "Write Serialized Files" when building assetbundles without changes

I have found some bugs regarding this. One of them is here . Unfortunately, I have not been able to submit a format bug for it before now, because I have not been able to reproduce it outside our main project, but I may be able to do so soon. Another thing I found is that Write Serialized Files takes significantly longer if you trigger a build with a scene open. Not entirely sure why.