@Muskabeatz and I ran KRs in X30 Masters last year on 58mm PCD hubs and wheels.
We ran Compkart 95mm hubs in the front and AMV 9F 95mm hubs in the rear.
We ran mostly 3F and 9F but also used Lynx and Tiger. We found the 3F very close to the stock KR set-up. When I back to back tested them, I found no performance difference.
Here is a link to the AMV 9F hubs. You can also used Compkart 95mm rear hubs.
Makes sense to me! I almost did the same thing when i switched my kid from CRG to OTK, i had several sets of CRG wheels and considered swapping hubs, but ended up selling all the CRG stuff and replacing them with OTK rims, just for ease of replacement in the future, since there is no local CRG guy and several local OTK guys.
Yes, you’re on the right track here. There’s no sense in converting everything to another PCD, especially when you have a proper range of wheels already on-hand.
I second @Paul_Montopoli’s recommendation for the CompKart front and AMV 95mm rear hub combo. This worked well for us when we were using the KR chassis. The standard KR hubs are 89mm in front, and 94mm in rear, so plan for that when setting your front width (I ALWAYS ran the recommended front width, but with one 5mm spacer removed to account for the difference in hub length).
Since you already own the wheels I’m sure you’re aware, but will mention anyways; be sure to account for differences in backspacing when changing from one type of wheel to another. Here are some offsets for different wheels I have used recently:
Lastly, don’t be afraid to try those MXC’s on your KR. Dalton Hanes recently won the IAME Grand Nationals aboard a KR with MXC’s. Their performance characteristics are pretty similar to the 3F, fwiw.