To be clear, @daemonfowl, if you edited the file and set the sysctl from 1 to 2, then started X without rebooting, X would not function.
- Editing /etc/sysctl.conf does not change any active settings, only the contents of the file.
- That file is only read by rc(8) at boot time.
- While many sysctl settings may be set at any time via the sysctl(8) command, the aperture sysctl can only be set when the securelevel is set at 0 or below ... which means, for normal systems, only during boot.