I fear we cannot solve that because the pad has not latching feature enabled.
Can you check the documentation if the pads can be setup this way:
Press => light is on => CC message with value 127 is sent out => light stays
Press again => light is off => CC message with value 0 is sent out => light remains off
When this can be changed then in Gig Performer you have to uncheck “Momentary to latching”
When this is not possible you should think about selling your Launchpad any buy the next generation.
What you could also use is an iPad with Lemur running on that.
You could easily build your own Gui or use that provided for Gig Performer.
Another alternative solution is Touch OSC
Or this brand new solution discussed in the forum: