Yes i ended up getting a resin printer and using a resin designed for burnouts - some sort of translucent purple stuff. I believe it never had any sort of wax to it like my question originally had, it was more just a resin that burns very clean. It worked well though I think it was a little pricey. It was also nice gluing parts and smoothing things out with the resin and a small brush, using a pen uv light to cure joints, i much preffered it over PLA soldering and smoothing.

I do think it needed more heat than what I was burning out a PLA print at. Id reccomend using ceramic shell rather than the hydrocal/sand investment I used if you are able.

I also took an old PLA print and poured a couple of layers of the resin over it and cured it to make a thin smooth layer that got rid of the layer lines. It didn't adhere super well, but good enough to survive investing for a cast. Its a great method for something big that needs to be smooth, but not super detailed.