Hi Tony, Welcome to the Forums.
Nothing at all wrong with making your own plate. I prefer the aluminum ones, but I've used a phenolic for years. My only caution is that with the larger router, you may want to remove the router from the table when not in use. Over time it can bow/warp on you. Some have gotten around this issue by using a larger recess...on the order of an inch or so...to give the plate more support.
Woodworking is more than a hobby.
It is a journey of discovery,
An application of innovation and creativity,
And an opportunity at self improvement.