My first question is "why?"
If you're only changing the vid/pid to make the product appear different to anyone else's which is based on a CP2102, do you really need to? Can you figure out whether it is yours by probing the serial interface? Could you just change the vendor and product strings, instead of the IDs? How much user confusion is likely to arise if you just stick with Silicon Lab's vid/pid?
All of this dext scaffolding is quite painful to get right. The user is burdened with approval of the dext, but if you didn't change the vid/pid of the CP2102, they would not be, because the Apple dext is pre-approved.
I don't know if you can use the recommended approach here, of subclassing from a known DriverKit class, but overriding nothing. This is because AppleUSBSLCOM is specific to the Silicon Labs CP2102, its interface isn't in the DriverKit headers. You can't simply inherit from IOUserUSBSerial, because that driver doesn't know about CP2102, and I don't think you can inherit from AppleUSBSLCOM, because you have no header file for it.
I'd try two things:
go to /System/Library/DriverExtensions/com.apple.DriverKit-AppleUSBSLCOM.dext and copy the DriverKit-AppleUSBSLCOM-CP2102 IOKitPersonality from it, change the idProduct and idVendor and put that modified dictionary into your driver's plist.
Your personality is now referring to an executable which isn't present in your bundle, I don't know if that will work.
You may need to ensure that your dext contains some executable code, but this personality won't refer to it. Your code should already generate a do-nothing dext.
ensure that your app actually tries to activate your extension using
what does systemextensionsctl list tell you?
I use log collect --last 20 immediately after activation to give me a workable log archive that isn't too huge and isn't constantly changing where I can read messages which my be pertinent to my dext.
I don't use systemextensionsctl developer on any more. Its laughingly poorly documented - what is developer mode, for example (FB7656761) ?
As for entitlements, your hosting app needs the System Extension entitlement.
Your driver needs DriverKit (a boolean YES), DriverKit USB transport (a dictionary containing an array of idVendors, usually just one), and DriverKit serial family