I was always concerned with the comfort carrying so put off even trying appendix carry for over a decade, when I first tried it last year I quickly realized that it could be comfortable and was in fact the most comfortable way for me to carry, especially while driving or riding a motorcycle, as long as the holster either had a few specific parts or I added them myself. Here's what I did to make it work for me.
First, I bought a neutral cant adjustable ride height holster for the longer barreled version of the handgun I carried, I eventually replaced the handgun (Springfield Hellcat) with the larger version (Hellcat Pro) as well, placed it slightly to right of 12 o'clock, and adjusted the height to the point that the entire grip was about 1/2" above the belt line. Next I added a concealment claw and a foam wedge. Finally, I found that wearing my belt slightly looser and pulling my pants/belt up when sitting or bending solved 99% the issue of the holster digging into my pelvic joint.
This worked well enough with the "cheap" holster that I decided to spend the money on a Tier 1 Concealed Agis Elite and then added the wedge to that holster. This, in turn, worked so well with the Hellcat Pro that I even bought the same setup for my Sig 320 X-Carry with TLR 7. For the T1C's I set up the clips in the "Bravo" configuration.
I will also second the recommendation to watch the Phlster youtube videos for guidance on how to make this more comfortable for you.
ETA: I will also note that my concealed carry draw times decreased significantly, from ~1.9-2.1 seconds to ~1.4-1.6 seconds, when I switched from iwb at 4 o'clock to AIWB, but that depends on how much you have practiced your actual drawstroke.