How is the use of virtual consoles controlled in Debian 12

I noticed that in Debian 12 (amd64, but I guess that's independent of the platform actually), when a user logs into the graphical UI (Xorg based with nvidia), the GDM3 server no longer is active on :0 and switching users is not available as prominently as it used to be in older Debian distributions. Also, when going to the text virtual console with Ctrl-Alt-F[1-7] not getty process seems to be activated by default nowadays. This causes problems when I start an X server for remote rendering with TurboVNC and VirtualGL because startx then places the newly created X server port on :0 and prevents GDM3 from relaunching. Also, I can't simply enter a text console when the graphics is hosed. I did not find any mention of those changes in the bookworm release notes, so I wondered if I could get the old behaviour back? And on another note, if not, if there is some command-line tool to query the next available X server slot above a certain threshold? SSH X11 forwarding seems to be using to not interfere with X servers launched by GDM3, which I would like to emulate here.