I got a couple of Highwing LLC's teflon sheets for smoothing finishing tapes "without the mess." They work!
The sheets are thin, and allow the transfer of heat quite easily through them into the Poly Brush and tape edges.
When NOT using the teflon sheets, I had to clean my irons like everyone else a few times, as at 225* it is just enough to melt the Poly Brush and stick to the iron. While R65-75 reducer removed the accumulated Poly Brush easily, it was still another step. That does not happen when using the sheets.
The sheets also do a pretty nice job of keeping the Poly Brush in place, and not allowing the iron to create those micro depressions in it. The sheets allow for better smoothing without the creation of these "iron tracks"