PR #3215 is indeed large and complicated. Here are the reasons why:
1. It had to be. Many files use unls, some in unexpected ways.
2. There was no reason to be overly fastidious. I knew PR #3215 would succeed. Adding other PRs would have slowed me down.
3. Some changes could not be made outside the PR because they relied on code defined only in the PR.
4. The PR's size doesn't matter:
Summary
PR #3215 inherently affects many files.
I knew that PR #3215 would succeed. There was no need to fear impossible-to-correct bugs.
Edward