Export midi - all parts and not just a single ine

I’m trying to do some session prep using midi from Dorico score -
I’m attempting to do this by exporgting midi and importing that into my DAW.
But all I ever get is a single part (the top part)

I’ve looked at docs which say it’s all to do with selecting the correct layout option on the right hand side - I’ve tried every single combontaion I can come up wioth, selecting all parts, delselcting them,

I’ve also tried selecting all parts down the left hand side - but every time I go to export midi I just get a single line.
Perhaps if I just did a copy paste into a dummy project on the top line I might get all the data I need just to get the project out of the door, but there must be a way somehow to get all the midi from the score and not just a bit of it.

…I’ve figured it out - the parts were actually all there - but not being seen by the DAW because of the midi channel allocation.

Q… I wonder what would happen if there were more than 16 parts…?