Yes it will boot Catalina fine. The EFI seems fine. I found OC config app had a hide Verbose enabled. I disabled hide. See if that activates it.Which install page are you talking about? Mojave one?
Did you 1st check that the new EFI created with OC 0.66 is able to boot your Catalina (before creating the Mojave one)?
The bootloader looks like it is not installed or your NVRAM isn't native.
@CaseySJ I tried following the guide, but came across a problem. I started on the front USB connectors, but the first one I tried accepts only USB2.0 although it should be USB3.2 according to the labeling on the MB:thanks for your fast reply. Umm, I have to admit that I haven't yet configured the USB Ports. I will do so now following the guide here: https://www.tonymacx86.com/threads/the-new-beginners-guide-to-usb-port-configuration.286553/ and see if that helps.
You were right !
The ß2 has been successfully installed and has the 20E5686d version.
Then I have been able to install the full version downloaded on Apple servers.
This version does not have the same build number but this one 20E5686e.
Does it mean that developers are trying to track the bugs coming either from the update build or the fresh install one?