Not worth the risk of a blowout for me. Wax without wire foundation is comb for me. Too many frames have blown out during extraction...no matter what the speed was.
I've had some wax foundation that I haven't used up. Each year, I put two frames of wax foundation in each super. The rest is wired or plastic. The two wax frames are cut for comb honey and the rest is extracted. I had said I wouldn't order any more wax foundation after this is gone. But it really has been "fun" to have the comb each year. Some older folks in town want that because of the memories it brings back of their fathers or grandfathers.
If you have only wax right now, I'd buy some wired and do what I do. That way, you can extract and keep the filled out frames for the next flow and you will have some good comb honey too. The best of both worlds!