I think this sounds a good idea-
"Pending the outcome of split payment pilots in Scotland, the Committee says that where claimants have dependent children, the entire UC payment should be made to the main carer, by default. Where alternative split payment requests are permitted, the higher proportion of the split payment should remain with the main carer other than in exceptional circumstances."
from Work and Pensions Committee review into universal credit. Hope this might happen. It does with tax credits, for example.
www.parliament.uk/business/committees/committees-a-z/commons-select/work-and-pensions-committee/news-parliament-2017/universal-credit-domestic-abuse-report-publication-17-19/