DDS import very slow. Single threaded

When importing dds for cube maps the performance is horrible. I’m running on a 4790k and the performance for importing a 1024k cube map can take almost 8 minutes and a 2048k cube map will take I don’t know how long because I have to go away and come back. It takes at least 15 minutes or more. Most notably is this process is single threaded. I would imagine this has to be a embarrassingly parallel process so it seems odd that it is single threaded. Any chance to improve this process as it is time consuming to spend so long importing especially if you are making small corrections and re importing?

Also once you import these textures it is painfully slow, taking 5-6 minutes just to change the brightness on the texture. I’m really not sure how anyone can use this workflow. Am I missing something?

is this a known issue?