Bowser's Ledge Intangibility Refresh

Bowser has one of the easiest ledge intangibility refreshes in the game, needing only to fastfall and doublejump to retain a cycle of full intangibility. Ideally, staying fully invincible at the ledge should be something you're able to do without even thinking about it-- you should be using that time to look at your opponent and react to how they're moving about the stage to try and find an opening. Since it's composed of just two actions, fastfalls and doublejumps, there is actually a wide range of frame data with which the technique will work. I will detail the two that I have personally practiced, the lowest and highest variations of the intangibility refresh.

For the lowest variation of the technique, the inputs are very simple. It just requires a fastfall from the ledge as soon as you're actionable, then a doublejump after 7 frames. It's important to note that you're still fully invincible if you fastfall for 6 or 8 frames as well as the 7 frames described above, but by aiming for 7, you'll be fully invincible even with a missed input as long as it was only a frame off:

Low Variation Frame Data
1: Mandatory Cliffcatch Frames (8 frames total)
2: Mandatory Cliffcatch Frames
3: Mandatory Cliffcatch Frames
4: Mandatory Cliffcatch Frames
5: Mandatory Cliffcatch Frames
6: Mandatory Cliffcatch Frames
7: Mandatory Cliffcatch Frames
8: Mandatory Cliffcatch Frames
9: Fastfall (7 frames total)
10:Fastfall
11:Fastfall
12:Fastfall
13:Fastfall
14:Fastfall
15:Fastfall
16:Doublejump (22 frames total)
17:Doublejump
18:Doublejump
19:Doublejump
20:Doublejump
21:Doublejump
22:Doublejump
23:Doublejump
24:Doublejump
25:Doublejump
26:Doublejump
27:Doublejump
28:Doublejump
29:Doublejump
30:Doublejump
31:Doublejump
32:Doublejump
33:Doublejump
34:Doublejump
35:Doublejump
36:Doublejump
37:Doublejump
38:Mandatory Cliffcatch Frames (Same as frame 1)

For the highest variation of the technique, the input is slightly more difficult, due to the fact that you need to fastfall twice during the cycle. It is a fastfall from ledge, then a doublejump, then a fastfall again at the pinacle of your doublejump's height. You can begin your second fastfall on any frame from 22-24 and still retain full intangibility throughout the cycle. I'd recommend aiming for frame 23 because you will still be fully invincible if you're not frame perfect on that input.

High Variation Frame Data
1: Mandatory Cliffcatch Frames (8 Frames Total)
2: Mandatory Cliffcatch Frames
3: Mandatory Cliffcatch Frames
4: Mandatory Cliffcatch Frames
5: Mandatory Cliffcatch Frames
6: Mandatory Cliffcatch Frames
7: Mandatory Cliffcatch Frames
8: Mandatory Cliffcatch Frames
9: Fastfall (1 Frame Total)
10:Doublejump (23 Frames Total)
11:Doublejump
12:Doublejump
13:Doublejump
14:Doublejump
15:Doublejump
16:Doublejump
17:Doublejump
18:Doublejump
19:Doublejump
20:Doublejump
21:Doublejump
22:Doublejump
23:Doublejump
24:Doublejump
25:Doublejump
26:Doublejump
27:Doublejump
28:Doublejump
29:Doublejump
30:Doublejump
31:Doublejump
32:Doublejump
33:Fastfall (5 Frames Total)
34:Fastfall
35:Fastfall
36:Fastfall
37:Fastfall
38:Mandatory Cliffcatch Frames (Same as frame 1)

Pros and Cons
Both variations of the refresh are 38-frame cycles that are fully intangible, so on paper the highest variation is worse simply due the fact that it requires more inputs, and thus is easier to mess up. I think that it isn't so clear, though. The higher variation looks much more vulnerable, due to how high up off of the ledge it goes, and thus could be an effective bait to opponents unfamiliar with bowser. They may be more likely to try to contest the refresh if you're going higher with each one. The lower variation also poses a higher risk of SDing, as if you accidentally fastfall for too many frames initially, you won't be able to get back up with your doublejump, giving your opponent a giant window to hit you when you're forced to Uspecial to the ledge. Obviously it's best to practice and master both variations so that it's fully down to muscle memory to mitigate the risk of SDing.