Shimming the rotors was easy. FYI my hubs are Stans Neo on the OEM wheels and DT Swiss 350s on the RCG 36 wheels. Once I mounted the rotors on the RCGs and put them on the bike, the outside pads were lightly touching the rotors. So I realigned the calipers to center the pads over these rotors. Then I put the Stans wheels back in and sure enough the inside pad was lightly touching the rotors. I removed those rotors from the hubs, put on one 0.25mm shim, then the rotor and nut. Put the wheels back on and that's it, the rotors were nicely centered between the pads. I don't know how many times I've switched the wheels back and forth since, with zero rotor alignment issues. FYI the bike has thru-axles, not QR skewers, so the hub alignment in the frame/fork is the same every time.

Re geometry, there are gravel bikes that are much like endurance road bike geometry with maybe a longer head tube. Others are more cross-like.

Here is a link to the shims November sells (and included free with my wheels) https://novemberbicycles.com/product...shim-pack-of-4

And here's a link to Dave's musings on this topic. https://novemberbicycles.com/blogs/b...sets-of-wheels