Displaying only the luma channel in Speedgrade when using direct link. Is it possible?

Question

Hi!
The idea here is to be able to display only tle the Y (luma) channel i preview window of Speedgrade. I know that this is possible when grading in a new crated project in Speedgrade.
Timeline/View/Channel Display. I know that there are shortcuts to display the separate RGB channels but there is no short cut to display the isolated luma.
Do You guys know if there is a solution to customize shortcuts in Speedgrade? Or is there another method to display the luma when working in SG on a directlink created project?
The reason for this is a project thats supposed to be graded in BW with an ability to manipulate colors/channels values underneath the bw display. Because after adding the BW "filter" or decreasing the saturation value all of the controls become "some sort" immune to  color data below the bw grade witch gives no ability to preform corrections to particular channels/ colors with live preview in BW. Of course we could try to desaturate the monitor but turning the colors back and forth every time would be a  coffin nail in production time
Any hints greatly appreciated.
Cheers Max

Answer 1

Hey Max,
Correct me if I'm misunderstanding your issue, but I believe Speedgrades layers apply effects linearly based on the information passed to them by the layer directly below. Could you achieve your solution by using two  (or more) primary layers, with the bottom layer being used for manipulating colours, and with the top layer to desaturate?
If switching back and forth is important, you could add a single effects layer over the entire projectt on a track above, and then just apply a primary that desaturates to that effects layer. Then you could just switch it on and off by toggling the visibility of the track.