Hi! Co-maintainer here, you can find the differences in the github repo: https://github.com/ublue-os/bluefin
I checked the github page you link and can find no differences listed, just three bullet points that appear to have be written by a PR team. You say an Ubuntu Desktop experience melded with Fedora Silverblue. Don't you mean GNOME? Ubuntu isn't a desktop environment, it's a Linux distro. GNOME is the desktop environment. That seems like an embarassing blunder in your copy when you claim to be building a distro for "serious" developers.
If it weren't open source, I'd think this was a scam. Weird choice.
Back when, after the world didn't end after Y2K got patched and saved it, I was getting tired of Windows and none of my Macs were up-to-date enough to handle my writing workload, I gave Caldera OpenLinux a shot. Ended up compiling everything myself and used that for two years. Had a copy of MetaFrame laying around from a completed project, so I installed it on Windows 2000, and served Office apps over the network so I could use Word in Linux. I've had something running Linux since.