I agree its a bad decision by Dolby. You can transfer the top layer of a 7.1.4 bus to another quad bus then assign those four channels as objects to get around it.
Here we discussed it.
At the end of the thread I came up with this method. I think it can be even simplified by making an “object bed”. By creating multiple (12) objects from the bus in one command. But I have yet to use or test that method.