I have not. I have run the Aero Hunter Kestrel.
I have 2 years of work related experience with a rock climbing sit harness and chest harness. I can tell you that pretty much any saddle you get will be much more comfortable than a rock climbing harness.
Be very careful using something as a "saddle" or "safety restraint" if it wasn't intended for that use.
The sit and drag as used as the saddle while still hooked up to the harness. I’ll order a tetherd but was playing on YouTube.