I've managed to get up to world 4 now:

I optimized both the suck and the invasion, I'm so happy!

its a sunglasses face ya dinkleberg 8 (eyes) ) (mouth) 8) ya feel me?

1. That's what someone told me. I haven't actually compared holding down when swimming to regular swimming, but I assume holding down is a slight bit faster.

2. For the clip? I figured out that it's triggered by letting go of down and jumping at the exact same time. It's not as big of a timesave as hitting the very specific invisible blocks, though.

3. Very, VERY specific timing. I'm actually surprised it works.

4. Yep! And you're right, I found it a little too precise, so I figured out a way to beat the level by flying. A lot of useful skips/optimizations come from flying toad, huh?

5. If you look at 11:35, you'll see that I land on the grey pipe. That gives me a significant amount of flying distance which allows me to reach the green flying turtle I landed on. It is possible to get to the red flying turtle if you don't land on the grey pipe, but you have fewer options that way.

6. Alright, thanks! And I hope your computer starts feeling better. If it's still running SMBX too slow though, you can try using SMBX Beta 3 since it uses a modern version of OpenGL rather than an outdated version of DirectX.

7. I plan on switching to Mario at the beginning of world 6. There are some useful strats I'll miss out on, but I believe it's necessary. At least I can hold on to the hammer that way.

8. Unfortunately not, I haven't played Lowser's Conquest yet. I'm focusing all my time and energy on TI2 right now.

9. Thanks! I hope I can get this run finished, too. From the looks of it, I might be able to get around 36 minutes with all the current timesaves, though I have even more for later on.

Things have been slower recently, as I've had to pay attention more to college classes. Here's a recent strat I made for world 5: