Keeping pull requests small without slowing delivery

Our team agreed to cap pull requests at roughly four hundred changed lines, but some features simply touch many files. Splitting them created a chain of dependent branches that nobody enjoyed reviewing, and integration bugs appeared late.

We are now experimenting with feature flags so unfinished work can be merged safely, plus short design notes before large changes so reviewers understand the direction early. It feels better, but flags add their own maintenance cost. Do you use stacked changes, flags, or simply accept larger reviews for certain kinds of work? I would love to hear what actually stuck in your team.