Geez, I've been looking at diff programs and the personal licenses for them are so expensive. I get they're incredibly useful when you need them but I personally don't need a 3rd party differ very often. Kaleidoscope is $250ish IIRC.
The VSCode extension "Diff & Merge" give you the right/left arrows to merge lines if anyone is looking for a tool that does that. I haven't needed another one since I found that.