Seems like yes. There's keyboard shortcuts for scrolling listed here:

https://cgit.freedesktop.org/~dvdhrm/kmscon/tree/docs/man/km...

Perfect. In that case I'll be trying it out on a headless machine soon.

FYI, seems like this fork is a lot more maintained, so you might have better luck with this.

https://github.com/Aetf/kmscon

"That one got removed from the Linux console years ago and I miss it."

https://seclists.org/oss-sec/2020/q3/174

He proposed a patch but instead Linux kernel developers disabled scrolling!

You can still satisfy the need for scrolling by using NetBSD.

(I use both Linux and NetBSD)

With the --sb-size flag one can purportedly set the maximum lines of scrollback in kmscon.

If you are OK using gnu screen, you can auto spawn screen if tty is /dev/tty2 - tty6 (adjust if you allow logins on other ttys). Screen will mess up ability to run startx, but if not using X, use screen on /dev/tty1 - tty6.

I do the above (via a shell snippet in /etc/profile.d) to get scrollback and an idle lock, via screen, on tty2-6, and, if tty1, add an alias that invokes vlock after startx exits to lock the virt console that X is using on exit from X.

But, KMSCon looks worth checking out.

Sticking with screen. Installed kmscon, manually ran kmscon on a single virtual console, switched back and forth from kmscon to X and back three times. On the third time, X shutdown like it detected a conflict (it looked like a crash, but the logs showed an orderly shutdown of X). Current setup with auto spawned screen instances is stable.