How to disable VT/TTY switching via Alt+Fn keys

[MansomeLamb]

Hello, I have a Retropie project using the updated 4.4 image, running on a Raspberry Pi 3 B.

I'm using Attract Mode as the front end to launch DosBox and Linapple emulated games, so the primary controller is a keyboard. In order to prevent users from exiting Attract Mode, I disabled the keyboard shortcuts to exit the front end, as well as the ctrl-alt-del.target (switched the symlink to /dev/null), but I am having problems disabling the tty switching via Alt+Fn keys. The end user can still press Alt-F4 (for example) during emulation, which switches to a different virtual terminal but does not close the emulator, and leaves the pi in a state that requires a reboot.

I've tried to follow other posts online pertaining to Debian, Raspbian, and Jessie. Editing /etc/X11/xorg.conf and adding

Section "ServerFlags"
Option "DontVTSwitch" "true"
EndSection

That didn't work, unfortunately. I'm wondering where the functionality for these key combinations is stored and if I can disable them. Thanks.

[mitu]

Modify /etc/default/console-setup and set ACTIVE_CONSOLES="/dev/tty1 so only the 1st TTY is active.

[MansomeLamb]

Thanks for the reply. I tried editing /etc/default/console-setup and changed ACTIVE_CONSOLES="/dev/tty1" but I can still switch to tty2,3, and 6 by pressing the corresponding Fn keys while holding alt. Tty4 and tty5 seem to be disabled, so maybe I'm missing something and the other 3 are being activated at login?

I also edited NAutoVTs=1 in my systemd logind.conf, but this also hasn't stopped the additional TTYs from appearing.

[UPDATE]
Had a feeling the TTYs still active were being started somewhere at boot. Checked my /boot/cmdline.txt and changed console=tty3 to console=tty1 and now Alt+F3 is disabled!

Still need to disable Alt+F2 and Alt+F6. Any suggestions are appreciated!