Peculiar behaviour when copy/pasting from piano staff

Last night I sketched out a four movement work for orchestra, using the MIDI keyboard straight into Dorico (no, not real time–I don’t quite think that quickly) with the intention of copy/pasting different components of it into a short score this morning.
It wants to copy onto two staves, regardless of my choices (such as nominally selecting only one of the two staves of the piano), unless I only make one target staff available.
And it doesn’t seem to want to copy in at least one case of this, if I have selected ‘to end of flow’; otherwise it can indeed copy. This was fine on the earlier flows, but balked on the last flow.
So first of all, are there any strategies people might have for composing with Dorico? Up until now I’ve only made guitar music or orchestral arrangements of guitar music with Dorico, and it’s wonderful for those.
I’m planning to do a lot of this kind of composition in the new year and initially thought that I would simply leave two-staff instruments (piano, harp organ etc.) out of the early part of the process, and go MIDI->guitar-staff on its own, since this works very well, and I’m used to it–except that I won’t get out-of-range playback, which can certainly come in handy. Does anyone know of an instrument traditionally written on one staff, which has a range of a full orchestra? I imagine future iterations of Dorico will be able to alternated between different renderings of either tablature or standard staff for theorbo or other lutes, although I can see how it might not exactly become a priority for some time :wink:
Anticipating a likely suggestion: no, I want to do it all in Dorico–not sequencers, nor other fine software. Both rhythmic playfulness and error-correction–vital if you’re as messy a composer as I am–are peerless in the Dorico environment, and I’d like to keep the flow going, rather than leap into other clunkier solutions.
So, here’s what I’d like for Dorico in this narrow future: keyboard staff behaviour that is either clearly separate staves or clearly one instrument so that its two staves can map onto one (such as a guitar) if copy/pasting. Ideally a way of toggling between the two behaviours, since each has its merits. And maybe even a way of being able to have, if desired, an option of a single staff for piano, for which there must be many uses.
And, unconnected, except also on the subject of keyboard, an optional ability to divide input about a predetermined split-point (middle-C being the obvious default) between treble and bass clef-domains so that if I really want keyboard music to act like keyboard music with a minimum of fuss, I can have that from the start.
I hope I don’t come across as stroppy in this. Dorico is already wonderfully powerful and elegant, and the frustrations are few, if, as in the case of Sibelius, I do come up against the edges from time to time, because of my peculiar needs and self-perceived optimal workflow. I’m very grateful for what it can do, and for the care and attention the team gives to it, and to us.j

Regarding copy/paste: Dorico does attempt to copy from instrument to instrument, rather than from stave to stave. This means for example, copying the two piano staves to any other single stave instrument will ignore the second stave currently. There is one special case, which you are using there, which allows items from one individual stave to be copied into any other individual stave. However, that special case will fail to work as soon as an item is selected that belongs to all staves together, which would be the case for tempo marks for example. Deselect those, and you should be able to copy as you did with the other flows.

Thank you! It works!j