yes you could do this if you have enough outs available for other things on the GLD and yes each out can have an eq and yes, they would need to be part of every scene….
BUT I assume you are taking the main outs of the 300 to the DSP? Or were you using Matrix outputs? The DSP may still be the easiest way to do this or use Matrix outputs on the GLD.
Many options, but keep it simple. If the current DSP works fine, it still might be the best solution.
Just my $0.01 worth.
Bob
GLD80, AR2412, 2xAR84, Dante