https://imgur.com/YFLdxcx -- increase is linear, shape doesn't change - very good measurement conditions.
https://imgur.com/l563K5B -- obviously overdriving and distorting at higher levels
"Would there be an affect on the color amp response from the other color circuits such as the oscillator or demodulator?" - No.
"where I have landed for now" - I'd say leave it this way for now and see how the picture looks, but it still is strange that you cannot get the response higher at 3.08 MHz.
Could you remind me where on the schematic is the sweep signal injected?