Hi,
If redesign:
Then I´d add an input filter at the ampifier, just to reduce input bandwidth and avoid amplifier ringing.
A series R may be sufficient in simplest case.
***
I know many designers use the true GND_plane (red) in combination with the copper pour (blue).
I´m no fried of this, because the copper pour is not much better than single wires.
--> It´s far better to not use copper pour but use short GND wires to vias to the true GND_plane.
You simply can use your layout and follow the signal paths and their associated GNG_return_path.
Sometimes the return paths are more lengthy than the signal paths and enclose a big area, which is a measure for EMI/EMC antenna function (transmitting as well as receiving)
Klaus