Yes, that’s the thing, no guarantee.
Even with a bit of a sub-par GPU, it should just happen more slowly. Like I say, I did install the engine on a Mac book, and an Mac mini.
The mini went into orbit, and couldn’t handle even basic tasks, but it was still possible to install.
I’ve had a rummage around and see people having problems with Big Sur, but I also saw someone who managed to get it working with the GPU below yours ( M370 ).
If you take a look at the running tasks while it says 34%, you should see several tasks called something like ‘shader worker’. If you do, and they are consuming CPU, it’s working. You might have to wait a very long time, but it will get there.
If you don’t see them, it has just bombed out.