Aleatoric piece and music frames idea

One more thing about the music frames. I found a serious problem using them in my idea of aleatoric piece.
When I create new material and create new bars in previous pages, everything is in the right place in the master chain, because I am using „lock the frame”. But it’s not applicable for my second frame chain, which I use for aleatoric parts. So, the music frames of my second chain are stick to the particular page number, the material from master chain moves to next page and my score looks terrible.

Is it a way to glue music frames from second frame chain to the particular bars of the first, master, frame chain?

Or is it a way to tell Dorico to not change the pages in particular flow? Something like „lock the flow”. E.g. I could create new flow for each bars, where I have aleatoric music and I want to lock all graphical elements on that pages. And if I change anything in previous flow, Dorico won’t change my aleatoric flow.

Edit. Apart of it, I noticed, that my manual staff spacing in master chain came back to the automatic properties. If you look at my example from first post, the staffs of „Vl 1,2” and „Samp.” parts went up, near to „drtt.” staff.