Sustain pedal with second keyboard

My main keyboard has a sustain pedal attached and works fine with sounds played with that keyboard. I also have a second keyboard which I use for different sounds (on different channel strips with the midi input assigned to that second keyboard). Are there any ways of getting the sounds I play on the second keyboard to respond to the sustain pedal from the main keyboard? Both keyboards are sending midi notes on channel 1. The patches are aliases in order to save memory as they are used in different combinations elsewhere in my concert.

The only way I can currently achieve this is by assigning the channel strip to multitimbral input, but that causes MS to crash if I move the patch up or down in the set or across sets. So I'm trying to find alternative ways that don't need me to use multitimbral assignment.

Thanks for your help.