You’ll also have to keep track yourself of system breaks and unison bars. For example, if a divisi passage begins in the middle of a system, Dorico will show both violin staves, since neither one is completely empty. But then you’ll have to manually copy the music from one staff to the other for the bars at the beginning of the system where the music is unison. And then if the casting off changes, so that one of those bars flows backwards onto the previous page, you’ll need to catch that and delete the music from one staff in that bar.
Alternatively, you could use manual system breaks to make sure that each divisi passage starts at the beginning of a system and ends at the end of one, but this may make for unattractive horizontal spacing in places.
If you use Dorico’s native divisi functionality, then the program will automatically take care of all of this for you.