Just wanted to add that there are two more GI systems. You have LPV, that it’s of low quality but dirty cheap, and then you have AHR( that’s what I’m working on), that provides a quality a bit lower than VXGI but runs faster. Also doesn’t supports point lights or multiple bounces yet, but it does supports reflections.
There’s also DFGI, but not sure on the state of that particular system, haven’t heard anything about it in a while.