I had a basic Big reactor powering my new base and a MFR laser drill limited to 3k RF and yet I seem to be going up and up in Yellorium stock without mining. It does help that in Monster the Nether Uranium Ore Macerates/Pulverizes into 4xYellorium Dust.It appears likely the MFR laser drill requires more energy than you'll ever get out of the resources you mine with it....
And from what I can gather it is the Lime Laser Focus that boosts Yellorium drops(makes sense since its categorized as Uranium).