This info is posted on the W1SFR site:
It shows the measured SWR without a tuner for a wire length of 41 ft (scroll to the last page to see the table). What isn’t clear is if the measurements were made at the matching unit or at the end of the feedline. I only make measurements at the matching unit/antenna as the SWR readings will be lower at the other end of the coax feedline due to losses.
In any event, nothing magical about a non-resonant random wire antenna. The SWR will be high on certain bands depending on the wire length you choose. I see that W1SFR suggests the SWR on 30m with a 35 ft wire will be 8:1. Its been a while since I tried to calculate the losses on a coax feedline based on antenna SWR. However, I remember the ARRL site has some good tables to reference that will give you a good idea.
I’ve never tried using a random wire antenna for SOTA but I know WA2USA does with good results. I believe he uses a separate counterpoise wire and I forget how long his feedline is…probably really short!