How to set 'bars per page' for each flow separately

Hello everyone.
I have project with a lot of flows and would like to know, if there is a way to set bars per page for each flow separately without being forced to use system /frame breaks.
Each of my flows has quite different ‘bar fillings’ - say one flow with 12/8 signature full of quavers / semiquavers, which means we can have only one or two bars per page here.
Another flow comes just with semibreves, so here we can have up to eight bars per page or more.
The flows a quite long, and as said before, there a many different flows in the project.
When I set bars per page to say 4 in the Layout options, this may be fitting for some few flows, but for the most it is not.
So it would be great if I could adjust this for each flow separately. But I did not find a way, have I overlooked something obvious?
Thanks in advance!

You can’t vary the fixed casting off settings by flow. Instead, try using a note spacing change in each flow. In flows with longer note values, reduce the ideal space for a quarter note; in flows with note values shorter than, say, 16th notes, try increasing the ideal space for a quarter note.

https://www.steinberg.help/r/dorico-pro/5.1/en/dorico/topics/engrave_mode/engrave_mode_note_spacing_specific_point_in_layouts_changing_t.html

Thank you, Daniel. Just tried it. Note spacing changes works really great, better than bars per pages as they are more dynamic.