Also splitting the 250-line change into 50-line parts will probably involve more total lines - to ensure it can be done piece-by-piece then fit together later.

Also splitting the 250-line change into 50-line parts will probably involve more total lines - to ensure it can be done piece-by-piece then fit together later. So not only is it more time per line, it's also more lines. Basically the only benefit is PRs per day, which is... not useful in itself.