Renaming the kexts is indeed sufficient. For instance:
itlwm_mojave -> min kernel = 18.0.0, max kernel = 18.99.99
itlwm_monterey -> min kernel = 21.0.0, max kernel = 21.99.99
With Clover, you would have placed the different itlwm kexts in the dedicated macOS version folders (eg: 10.14, 12), leaving the other ones in Other folder.
Sure. You can use settings to loading only some kexts for each macOS version. You only need to set the kernels.
MinKernel -> lowest kernel version your kext will be injected into, see below table for possible values. Ex. 12.00.00 for OS X 10.8
MaxKernel -> highest kernel version your kext will be injected into, see below table for possible values. Ex. 11.99.99 for OS X 10.7
https://dortania.github.io/OpenCore-Install-Guide/config-laptop.plist/kaby-lake.html#kernel