Vertical Justification before page break

USing Musescore 3.6 I have reset all styles on a long piano score which has twelve sections separated by vertical frames. I usually have a page break at the end of each section.

However in cases where the final page of a section only has a few staves, the justification algorithm spreads them out equi-distantly down the page. How can I reduce the inter-stace distance on these pages? Spacers are no good as I can only use them to increase the distance, not reduce it.

I have tried varying "Factor distance between systems" down to ~1.1 but that ends up negating all the justification benefits on other pages.