I follow almost the exact same algorithm, but with 6x soul frames and no Mutator. I had been trying with a stack of uranium in the mutator, but I kept getting swarmers of the new species. I hadn't thought of trying 1 uranium. I'll try that - it seems cheaper and easier than using 6x soul frames.
I use a single mutator with uranium (the raw stuff, the compressed ingots don't work) and a frame housing with a single oblivion frame. It's quite lovely. With all the bees Extra Bees en Magic Bees add you really can't do it the oldfashioned forestry-only way. That would take ages.