You can test by yourself. Just compile latest version of opencore from github and enable ProtectUefiServices and DevirtualiseMmio!
I have tried on 10.15.3 install. And got no more allocation error. Just got KP while loading kernel. And thats all test that i have done.
Good news everyone!
After that commit https://github.com/acidanthera/OpenCorePkg/commit/6d61426da5e89a33801c9f8a8f563861ed35d883
Opencore support Ice Lake. Just have tested it right now. No more allocation error.
Just build new version of opencore and enable ProtectUefiServices and...