I used Xtol at 6 or 6.5 minutes, 68F (can't remember right off the top of my head).(posted 9150 days ago)What I do is rate the film at ASA 100, then adjust for the filter. B+W 092 (ASA 12) gives the best effect, extremely close to Kodak HIE. Also, Ilford sells an opaque filter specifically for their film, and it should be fine for Konica. B+W 091 (ASA 25) (for my neck of the woods) gives good tonal seperation between deciduous trees (white) and connifers (grey).
When I used just a red filter the film was nearly completely uninteresting. I only got deciduous trees looking white.
Another thing I do is bracket two stops up and down, but usually my first shot is right on. I shoot with 120 on 6x7, and I shoot two rolls per scene. On both rolls I shoot a sequence each with 091 and 092, and I process one roll N and the other at N-1. Don't bother pushing these films. There just won't be anything there. If you absolutely have to have the speed, use Kodak HIE.