[Enhancement] Root Mechanic functionality, Channel Mechanic enhancement

[Tanis468]

Reposting here at request.

The Root mechanic describes itself as an effect that locks a target in place, but still allows them to look around. The actual result traps the target's view within a window so small it practically amounts to being frozen in place.
Preferably, this effect would instead only prevent locomotive movement, not merely looking around.

A further enhancement would be to add this as an option to the Channel mechanic.
It's currently very inconvenient to create a stationary channelling spell that requires the caster to aim, as their viewpoint is locked in place.