ok, well:
after i upgraded the bela version with the update board script i tried to compile my patch, here are my findings:
when no midi device is connected the heavyprogram outputs midi on the virtual midi device, of course if i select channel 18 (as in my example) it is restricted to channel 16.
if i connect a midi device to the host port (and therefore hw: 0.0.0 becomes the second midi port, addressed by channel 17-32) things do not work anymore. there is no midi output on the virtual midi port.
as i stated earlier this most likely is a heavy problem since also on midi input, channels above 16 do not work. so for the output case, there is no way to "select" the second midi port, since heavy simply does not recognise channels above 16. hmm...
i then tried my example with the IDE and libpd again and i now get the following error (after updating)
Segmentation fault
make: *** [runide] Error 139
this happens on all pd projects that i try on the board.
just for clarification, i also tried to send the message on channel 2, assuming that heavy would then just send on all ports that are enabled, but nope, does not work :-(