I never called them 'purist'. That was a term someone else came up with (I don't remember who), and for some reason it stuck.

The main source of the '93 mix for ESB was not the 70mm version, since that contained various editing differences, but instead a 4-track master that conformed to the 35mm version in length and content (with the exception of the missing snowspeeder crash sound, which was likely unintentionally omitted due to being an early generation copy that didn't have it; I've put it back in since all released versions of the film contained this sound effect).

Aside from small differences here and there, the 70mm mix of ESB did sound very similar to my 5.1 overall. Since it is not an exact replica, however, I gave myself a little more leeway in terms of whether the added bass was always 100% authentic or not, relying on my best judgement of what sounded good. In general, I would say that my version is what the 35mm version would sound like if unrestricted by the technical limitations of stereo optical format. So even though it doesn't duplicate a theatrical version in the strictest sense, it 'feels' quite authentic.

I'm not sure exactly how to describe it in less words than that. It may be best just to call it '1980 5.1' and leave it at that, I suppose.

As an update on status, I just realized I made a slight mistake in settings while I rendered it, so the 5.1 came out 3 dB quieter than I wanted it to. I must therefore correct this mistake and re-encode with the levels adjusted. It won't take long, since it's an easy fix. The actual work on it is all done at this point. "Almost there . . ."