Allow Ctrl to contextually toggle snapping as in Blender

[NathanLovato]

When snap is on, keeping Ctrl down temporarily disables snapping and vice-versa. For grab, rotate, and scale. It'd be great to have the same control with the addon, as there's often the need to place e.g. most things on the grid and fine-tune some things that don't perfectly match the grid when designing levels.

[imjp94]

To be honest, I don't even know you can do that in blender. Normally, I would use Shift for precise control.
Anyway, any shortcuts from Blender should fits well in this plugin.

[SLimeyMC]

SHIFT itself should have lower sensitivity for more precise tuning where as CTRL is used as the op says