Hi, I just replay base on my knowledge on Opencore.
Till yesterday, I am running macOS Catalina with Opencore 0.6.0. then I start to update my Opencore to 0.6.2 ( finally I found my mistake in config.plist)
1. I download Big Sur beta 10, fresh install using usb, install not start al all, hang. update opencore won't work.
2. boot to current running Catalina, and download High Sur beta 6 ( I not sure), try fresh Install run but still keep to boot to Catalina recovery. ( just understand request to format hardisk). than give up.
3. Boot to Catalina and install Big Sur Beta ??? ( but not beta 10) and run till finish install, and running Big Sur Beta ?( Public Beta)
4. Down Big Sur Beta 10, Install on current running Big Sur error, " cannot create reboot".
5. Try to install Big Sur 10 using usb also fail. Till know almost give up.
Sorry this only I know. I will update if I succeed.