Going from Linux Mint to Qubes OS could be rough. You’re warned ;) .

secureblue absolutely does.

Qubes OS does too. But that’s becomes dom0 and most of the qubes you’d interact with are just Linux. But the qube can be based on BSD instead. Heck, you could have it based on Windows even. These qubes are VMs; so you can basically do whatever you want with them. The heavy use of virtualization is exactly what makes Qubes OS as secure as it is.

Not the one you asked, but please allow me give my take on the matter.

Do you know if you can still do everything with it? Like atomic already has its own limitations and quirks. I can imagine there are bigger limitations with this.

Being derived from Fedora Atomic, already comes with its own set of limitations; like being limited in which kernel mods you can make use of (without reinventing the wheel), or how UKI is unsupported or how you should probably create your own image if you want to populate /usr. You can’t even install software from any repository; e.g. installing the ProtonVPN RPM has been hit or miss for me.

And, on top of this, secureblue’s hardening does (strictly) limit this even further. Most impactful, so far, would be the inability to use sudo or anything like it. Instead, run0 is suggested. I’m 100% sure that run0 is better. However, I’ve had at least 1 occasion on which the software doesn’t know how to properly interact in this setting. Ultimately, I’d have to give the blame on the software that doesn’t properly support run0. And, perhaps, you could help address the issue by opening a bug report related to it. But it’s definitely something to keep in mind.

Finally, note on first setup you’re walked through the many different additional hardening that can be reverted based on your needs. Just be aware of that fact.

Like can you install driver-level stuff like tablet drivers

Maybe. Depends on what exactly it is.

GPU/CPU control

I have.

udev rules

Shouldn’t be a problem either.

etc… I guess I don’t really know the implications of the extra hardening.

If you’re interested, I suppose the best course of action would be to find a secondary device of yours and setup it to your heart’s content with secureblue. Whenever you face a roadblock, consider paying a visit to their discord server for support; they’ve been a great help so far. If, at some point, you find something you absolutely can’t do, then you’d have to make up your mind on what you deem more important. Wish ya the best of luck!

To add onto what N.E.P.T.R said, it is technically possible to make a custom amalgamation of Bazzite with secureblue’s hardening. However, it would be neither here or there. Some discussion of it can be found here. IIRC, it was ultimately deemed counter-intuitive as a gaming-distro inherently conflicts with a hardened one.

Finally, we shouldn’t disregard the technical part of this; it’s IIRC one of the reasons why the Bluefin-variants of secureblue were eventually disbanded. It frequently had a lot of interesting bugs that were simply not present on other secureblue-images. This isn’t on Bluefin either, as the non-hardened edition worked as you’d expect.

I believe your confusion comes from the following line: “secureblue does not claim to be the most secure option available on the desktop.”

Which is simply their acknowledgement that more secure options like Qubes OS exist. Note, however, that Qubes OS is not based on Linux, but instead on Xen.