Disabling midi in for non-sync/transport

Is it possible to disable midi in for seq1/seq2/drum tracks? I’m really only interested in having midi in for transport control and sync, but it seems you have to also assign an input channel to these tracks.

My work-around is to assign them a channel I’m not using, but this also means I lose a channel between 1 and 16. It’d be nice to be able to disable midi input for these tracks altogether.