Good idea, 5 minutes ago I pestered because I forgot to run rectifier before Datheader 
This would also accelerate significantly Datheader on big triangle meshes as triangle to quad conversion can be performed by rectifier instead of Datheader.
One thing to maybe add in prefs would be equivalent to -a option, that prevents rectifier to create rect primitives when there is an adjacent condline. Default option should be -a active since this is the most conservative option (if you choose not to add another option for the sake of simplicity, then always activate -a).
This would also accelerate significantly Datheader on big triangle meshes as triangle to quad conversion can be performed by rectifier instead of Datheader.One thing to maybe add in prefs would be equivalent to -a option, that prevents rectifier to create rect primitives when there is an adjacent condline. Default option should be -a active since this is the most conservative option (if you choose not to add another option for the sake of simplicity, then always activate -a).