Inspired by Deevee’s An Exercise and A Round To it thread I developed this little utility.
The main attribute of the script is that it places your background plane automatically on the canvas clipping plane, sets a high mesh resolution and uses Flat Material. The other button is to automatically size the canvas area to your desired Texture Size, otherwise the script will just fill the current canvas dimensions and perhaps distort the texture you are wanting to use.
I hope this is of some use
Get it here
UPDATE 1.1
Problem with Clipping plane value fixed, be sure to upgrade to this version