In the same way that other region parameters can be normalized, the quantization settings can also be applied permanently to one or more regions. The Apply Quantization Settings Destructively function is especially well-suited to pre-quantization.
For example, if a recorded MIDI region cannot be quantized to a 16D Swing value without producing a few incorrectly timed notes, quantize it to 1/16 notes and then use Apply Quantization Settings Destructively. You can now use swing quantization on this cleaned-up version of the MIDI region.
Another example: If you are recording a hi-hat pattern consisting of 1/16 notes and one single 1/32 note, first play the rhythm (quantized to 1/16 notes) without the 1/32 note and choose Apply Quantization Settings Destructively. You can now raise the Quantization parameter value to 1/32-Note and add the extra note without incorrectly quantizing any badly played 1/16 notes.
Choose the desired quantization settings—including extended region parameter quantize options, if desired.
Choose MIDI > Region Parameters > Apply Quantization Settings Destructively (or use the Apply Quantization Destructively key command, default assignment: Control-Q).
Note: When this is done, it is impossible to revert to the original recording, unless you use Undo immediately after performing the operation (or use the Undo History command).