I pick Hard mode just because of some post for the recent submission.
Do note, sometimes in the menu, you can use a directional key at the same time you press the B button. Also, use the wraparound effect of the digits, as going down to 6 has us go 0 -> 9 -> 8 -> 7 -> 6 instead of going up through 0 -> 1 -> 2 -> 3 -> 4 -> 5 -> 6.
Finally, I have fooled around TASing the early parts of working on the railroad, using an identical layout to the submission. I suspect building it downward might still be done a little faster than how I did it, but it's only a quick test. Down is different from up, due to how the cursor works.
BizHawk has a... Certain learning curve. It also doesn't have my MtEdit script, I ought to figure out how to port that.