1 channel midi files?

[e8vww]

Great work with these, however they won't play out of the box when I try to output to a player piano. The piano is expecting the data all in 1 channel, but these files are encoded as 2 channels. Its possible for me to manually join the channels in logic pro, however this is very time consuming. I'm thinking it may be much easier for a member of the project to generate a subset that are converted to single channel midi.