These expression maps can be used by the Pro and Core versions of BBC SO. It should be possible to use them for the Discovery version by deleting or disabling the articulations that aren’t provided in that library.
It’s quite simple to map this library as most of the keyswitches can be directly linked to playing techniques in Dorico. Some of the techniques have long and short variants which can be accessed using Note Length conditions.
Note that articulations use the middle C=C4 convention.
Dynamics
Shorts use note velocity, longs use CC1.
The attached expression maps and percussion maps include most of the strings, wind and brass, but only a selection of percussion instruments are mapped.
BBC SO.zip (6.44 KB)
Manual: https://www.spitfireaudio.com/manuals-archive/bbc-symphony-orchestra/