There can be a lot of improvements, but a lot of them depend on rng (other ones depend on my personal skills), this time I had a good nether without any skeletons, but bad blaze spawning (could get 4 blazes and 4 rods of them so only need one blaze dupe), then I had duping issues, and while going up after getting the redstone I missplaced the crafting table, also the silverfish was a bad rng, they could spawn and instantly get into a bloks so i did not needed to fight them. I think it an be improved up to a total of 6 mins, less would be a too hard or impossible :D