Oh boy..., I think that you just booked a good chunk of my winter. Your setup looks so much better than the M2 flares that I can't not give it a shot. My bumper cover sits right on top of and bolts into the the splitter, like yours, so it just needs to be indexed and kinda snugged against the fenders. How are you aligning the fender and the bumper cover?
In the second pic from the top you’ll see an aluminum bracket held on with vice grips. We made that to push the fender and bumper cover out far enough to clear the extra tire width then used Rivnuts and hardware from Downstar to bolt them on. Before building it, I rolled and pulled the front fenders as far as possible then loosened all the fender mounting hardware and pulled them out as far as possible while keeping body lines in check and making sure the front doors open without any chance of contact. I ended up leaving a couple of the fender bolts out to allow for more width.
I actually still have my fender liners. I just trimmed where needed and zip tied the front of the liner to the mounts we made to keep them up out of the way of the taller tires. The rest of the liner uses OEM hardware.
Edit: I tore the leading edges of the front fender metal during trial/error and had to add metal and repaint them TWICE! 🤦♂️ Be careful if you attempt this. Even if you use M2 flares (I have a set) you’ll still have to cut out that huge box to clear taller tires. Those that don’t, DEFINITELY rub horribly at full compression. If they say they don’t, they’re full of shit. Taller tires will definitely hit that metal box where the three fender bolts reside.