I regularly sharpen my Big Ugly tools on the CBN wheels. The cutting material, Tantung, is silver soldered onto bar/sheet stock. No loading problems. I do keep the heel ground back like my bowl gouges, so I am not letting too much soft metal get on the wheel. I do use a big belt sander to round over the heel. I would expect that the planer blades would pose little problem. Using a bit of lapping fluid on my bevels is a regular part of sharpening. If you try to put it on the wheel, you get a racing stripe on your shirt...