Originally Posted by 63rickert

You don't want to be riding on sidewalls. At all. Don't do it.

You are doing beta testing. Wide rims changes everything and absolutely no one knows all the answers, or even all the questions. Until ISO speaks on the issue (which could be a while) the only authoritative guide is ETRTO. They say no more than 17mm internal width on the rim for a 25mm tire. 20mm rims don't work for them until the tire is 32mm. ETRTO is very conservative. If you and the rim and tire mfrs follows their guidance there will never ever be a problem. Riding outside their guidance you get what you get and you can tell us how it worked.

If cornering hard is what you do it makes little sense to use lower pressure in front. Downhill cornering all the weight goes to front. Cornering of any type involves deceleration and will transfer weight to front. Front/rear pressure differential is for getting maximum wear out of your tires.