Thank you! I tried to make the resolutions as high as I could while still having a relatively low render time (most of these took at least an hour).
I got Bryce 7 from Daz (before they went full NFT), they still sell it there but I totally understand not wanting to give them money. There's a Bryce 4 ISO on archive.org but it doesn't seem to have a serial.
That render is gorgeous, I'd love to have a render of mine used for something like that!