No question the edging plate works best with the 1010, but the 1400 isn't too heavy for the edging plate. I'd say the plate works very easily with the 1010 with almost no effort to support the router. With the 1400 is just takes a little more focus to make sure you're supporting it correctly.
With the 1010 this is a great accessory, if you want to use it with the 1400 try it out and if you'd prefer a smaller router instead you've got 30 days to return the setup.