Well, this may be embarrassing, but is it really not possible to select or specify a range of measures and force the number of measures per system for that range?
Also there is no command to move a measure on the previous of next system, apart from selecting the first and last note and using the “make into system” command?
Old habit, I know.
Thank you in advance.
Yes, at the moment casting off settings for bars-per-system apply throughout the whole layout. For manually controlling systems, your options are indeed system breaks/make into system.
I also had this Problem with custom bars-per-system.
Unfortunatley this makes creating Layouts very diffcult and time consuming! I used this feature in Finale quite often, especially for writing excersizes for my students.
PLEASE include this in future Versions!
It really shouldn’t make things very time-consuming, especially if you can work from left to right and insert system breaks as needed. If you need a system break that has the ‘Wait for next system break’ property set, don’t forget that you can copy and paste existing breaks in Write mode as well.
Some habits die hard, but it is much faster to select the measure and option+arrow to place it in place. Anyway Lili Harris wrote “at the moment” which seems promising.
My Dorico development colleagues continually impress me with the features they get into each version, so I’ve learned never to be absolute about anything, rather “never say never but who knows if/when” 
Not entirely true. In Engrave mode one can choose the first note of a measure and press SHIFT+S to start a new system, much like choosing a measure and pressing the down-arrow in Finale. Make Into System sets the beginning and end of a system, whereas SHIFT+S simply begins a new system and lets Dorico re-flow the remaining contents unless and until it finds another system or frame break.
Thank you! We are halfway there!