Giving a spin to Mathematica for OS/2 - Symmetrical Multiprocessing (SMP) for v2.11 with 16 CPU/Cores in VirtualBox 7.0.6 built from source in Metztli Reiser4 / Debian Bullseye backports AMD64. TigerVNC froze multiple times after connecting to the remote headless VirtualBox instance. Accordingly, I had to use Remmina again for a decent VNC connection. Nevertheless, OS/2 v2.11 VM falls back to use the PS2 mouse hardware which causes the mouse position to drift from the real mouse pointer as it is moved in both VNC clients.