I've done some experimenting while waiting for my 9 minute flat run to pass verification, and so I've included both my new route and some little things I noticed while playing.

First, my new route: -Collect 5 wood. -Make a wooden pickaxe. -Mine 40 stone, and craft the stone workbench and every stone toll except the hoe. -Hopefully, by this point you know where the ladder is. If you do, head down, shovel and mine, If you don’t, try chopping down trees and hunting zombies. Either are interchangeable, but get these resources nonetheless: -70 wood (For furnace, factory, chem table, and boat) -30 stone (for furnace and factory) -24 iron (to be 8 iron bars, for boat) -10 gems (for chem table) -36 sand (Turned into 12 glass, for chem table and glue) -27 ichor (For glue) -12 fabric (For sails; you won't need to hunt for fabric specifically, since you'll probably end up with just as much fabric as ichor.) -Now, you have a boat and need to reach land. Go to the surface and use it on any available piece of water (doesn’t matter if connected to the sea or not, nor underground or not. Underground is probably slower, though.) and you’ve done it.

Idk if skipping wood tier is faster or slower, but I think even if it’s slower, it’s on the right track. And since you can either go mine or tree chop, runs aren't dead if you haven't found the ladder after making stone tools, so it's more likely your run can make it to the end.

Other things: -Holding down mine is faster than waiting for energy to recharge. If you have no meter and are walking towards a block, however, it's probably slower than if you approached it with full meter. -Zombies like the overworld area much more than the caves, and seem to spawn a lot more frequently in open area. So clearing a massive area near the ladder, killing every zombie there, and climbing the ladder in and then out again is probably one of the faster grinding methods. Whether or not faster than doing overworld + cave? Idk. -It most likely doesn't matter where your crafting blocks are placed, as long as they're together and close to the ladder without being obstructive. -I tested it, and no, going to iron tier is most certainly not worth it. It's around a minute and a half to craft the anvil and one tool, and even if the iron sword kills faster and pick mines faster, you're better off staying stone. -If you mine in 1x1 corridors, the items have less area to spread, so you can have miniature time saves by not needing to run around and pick them up. When you have half the resources, you can always pick left or right and mine down that wall, so you don't lose time running back. Not gonna make or break a run, but wanted to mention it. -Collect the apples from trees. If you gotta kill ~30 zombies to get the ichor you need, you're gonna get hit. To kill them faster, you have to charge into them, almost guaranteeing you're getting hurt. And until we perfect combat, it's best you keep all the apples that fall to heal you. You should have just enough to keep you alive, even if you're sticking to mining the bare minimum trees and get hit more often. -Speaking of which, the side the MC swings the sword seems to have a larger hitbox, and holding down attack while standing still will practically guarantee you're not hit, as long as the sword's pointed to the zombie, which I dub the "safe strat." If charging, I've been hit most of the time, but if you charge them in such a way that you're running past them and grazing them with your arm, you don't get hit. If they're on the side you hold your stone sword, they die almost instantly. Not only does it saves time due to no heals, but it can lead to faster kills. So, even if you don't get hit much in your runs, but you're using the safe strat, there's a time save here of a few seconds. I have yet to master it, but I can get it once every 5 zombies now.

TL;DR -Route change skips wooden axe and shovel, pick only now, and the run is more flexible, depending on if ladder or not. -Hold down mine, waiting for energy recharge is not worth it. -Zombie grinding overworld only may be faster, can't confirm. -Optimal combat may be you running towards zombies in a certain way to avoid damage and instantly killing them, but it'll take some practice.