Another option is to put a larger UNPERFORATED barrier around your existing pipe.

A short piece of large diameter culvert would be perfect. Secure it to some posts driven into the pond bottom. The top of the pipe should be higher than your high water mark during flood stage when flow is also going out of your emergency spillway. (You don't want flood debris going over the top and plugging your standpipe.)

The lower edge of the large barrier pipe should be several feet below the water level at normal pool. (Depending on your water depth at the standpipe.)

That set up will allow water that is 2' BELOW the floating debris to enter beneath the lower edge of your barrier pipe. The floating debris should still be drawn to that area of the pond, but it should not clog your outlet. (You could still skim the area when convenient, just to keep that floating debris from eventually becoming organic sludge on the bottom of your pond.)

I don't know how "pretty" the solution needs to be at your pond. Large diameter culvert is typically very expensive. However, you could make do with an overturned plastic trashcan or 55 gallon drum, or even use old chain-link fence lined with heavy plastic. If using a "closed" system like a drum, then I think you need an open air hole on the top so you don't pull a vacuum on the large barrier pipe.

I do like your existing shield and plate. Hopefully, the solution above will keep your existing system running at 100% efficiency with debris-free water from below the surface.

The flip-side is that all of the floating debris in your pond is now going to STAY in your pond. That will cost you pond depth over the years in your tree-lined location. I suspect that some type of pond cleaning in the fall will greatly extend the life of your pond.