How about Shift+clicking (or similar) in the graph area or moving vertically on that line to set the Ratio (more accurately, the mouse vertical position would set the output level for an input level of 0dB)
Let's say I drag the Threshold to -20dB; then I click to set the output for 0dB input (e.g. where I have put a green star) in the mock-up (no, that star would not appear in real life)). That is at -12dB, so the Ratio = 20 /( 20 -12) = 2.5
Or, perhaps better, there could be a second (horizontal) line, draggable vertically to set that level.
Either way the two most important parameters could then be set without moving to the Processor panel. I was also trying to think of some way to set the Knee too ( Mousewheel over the point where the knee starts? (similar to mousewheel in the EQ plug-ins))

The same would apply to Processor 2. And go in all the Dynamics plug-ins / MXXX modules.
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PS
(a) I did not see where the 'Draw mode' (if that is the right term) was described in the Info windows,
(b) Is MMultibandDynamicsLarge = MMultibandDynamics + Processor 2 + Sidechain? Or are there any other differences?
(c) is MSpectralDynamics = MSpectralDynamics + Processor 2 + Gate? Or are there any other differences?
