Cal, mate you are trying way too hard.
There is no way that, whatever scan resolution you use, will a scan off a single 24x36mm frame off a roll of 35mm film be a better result than a +/- 20MP raw capture available from a FF 24x36mm DSLR.
And can you please, please stop calling them Ken Duncan style panoramas. As has been discussed earlier on the thread, even the almighty Ken Duncan uses different techniques to make his panos.
You will not find much better advice than is available to you when you re-read your own Topic ![]()
cheers