The “Length %” setting in the Expression Map editor seems to have no effect, whereas the new global settings in “Playback Options” are working, or maybe overruling the settings in the Xmaps. It should really be the other way round, the Xmap setting should overrule the global setting. Also, the “global curve power” should be local to each Xmap, or at least local to each VST instrument loaded…otherwise combining different libraries becomes very difficult.
I think that the length settings in the expression map editor should be cumulative. I’m not really sure yet how the settings here and the global settings should interact. The presence of the field in the xmap is largely to preserve the data imported from a Cubase xmap. In Dorico, some of the function of xmaps is subsumed a level higher into the playing techniques, which may make some of the xmap fields partially redundant (ie, given that the effect of staccato can be defined globally, is there any need for a per-patch override?)
Re: curve power - there is actually a setting for this for every technique in an expression map but there isn’t yet any UI to set it. The idea was absolutely that you would be able to use this to match the dynamics of different libraries. Internally we actually have 3 parameters to control this: separate power functions for the low and high dynamic regions and the level of the centre point. Currently though we only have the UI to set a single value.