Two drafts in. Pick each change by hand. One final draft out.
Paste or type two versions of the same passage. Differences are found word by word, including punctuation and spacing, and update as you type.
Tap a chip to keep that version. Tap it again to unpick. Undecided changes fall back to Draft A. Keyboard: Tab to a chip, ← → to move, A / B or Enter to choose.