multi midi port

I'm interested in how others achieve a multimidi port setup to an external sound device like linuxsampler.

I've built a default GM template in LS, with correct PChange numbers.
I'd like to route 4 midi ports out from mscore to LS, and have the correct PC triggered.

So far, i can get 1 port/16mchas working, but mscore simply won't use the second port. So my 'short' score of 19 staves is 3 short of a full playback. (violas/cellos/basses won't sound.)

The setup is simple with midiout (Alsa) from mscore going into LS.
LS is audio out in Jack.

Any help with this would be appreciated, as i anticipate using full score with decent playback, as soon as i can.

Call me old fashioned, but the playback to a decent library of gig files in LS is more than worth the effort.

Request for the future: That the number of ports out is increased to a point that enables us to use a port per staff. This is a respectful reminder for an FR i suggested a long time ago, to have 1 port/16mchas per staff, so we can change channel per note to trigger different articulations. I know the current setup is soundfont based, and that's already useable, but the expansion of playback to include a much wider range of high quality samples, i.e. gig files in LS, would seem to be a big step forward. (Strictly imho)

Alex.