I carry a G17 length pistol (have been for about 2 years now) with RMR in AIWB with this:
https://darkstargear.com/product/g19orion/
And this:
https://vdevgru.com/products/neoprene-aiwb-wedge-sponge
With this:
https://vdevgru.com/products/copy-of...y-belt-ver-1-0

I have been carrying AIWB since around 2008, and I will never give up the distinct advantages of AIWB over IWB as long as I can physically carry that way.