Your shield will get eaten every time if you don't touch the controls while you're in the Like Like. You need to press literally anything on the controller, the more things you press, the faster you get out, and if you get out fast enough, your shield won't get eaten
I don't have the willingness to spend the time on explaining it myself, the trick is called Early Lens, if you wanna do the research, or maybe you can find someone willing to explain to you in the Discord :)
I'm okay with requiring the collecting of all trade items if the verification team is willing to do that job.
Well you could skip all of the trade sequence, including Yoshi, and just get the Lens with Rooster if all you want is the boomerang. Would have to time exactly what's faster between just getting the things for Rooster or trading everything + getting hookshot. Unfortunately I can't actually do the tricks needed for the Rooster route so I can't do the timing.
The best way I have found is using a save manager on a homebrewed switch because it lets you clearly label which saves are what. Ultimately it is just a label and you can just make practice saves by making multiple profiles without the need for homebrew. Also as far as I know there are no emulators supporting save states for Switch games.
We would appreciate additional details on this "double jump" and what is "jumping in front of the ladder"? Because the way I see what could've happened is simply jumping onto the ladder and then jumping from the ladder, which you can do, to the top of the ladder.
I understand you may not have anything for this particular incident, but for future reporting, taking a switch clip using the capture button is a fantastic method of obtaining evidence for things immediately after you just realized it might be of interest.