Duck Tales is great, but it has a huge design flaw that proves glaringly obvious after years of absence--the pogo mechanic.
Before I get any further, I want my games to be tough as coffin nails, but I also want some standard of living: customizable controls, decent options, good hitboxes, etc. Duck Tales offers none of this. At the other end of the spectrum we have Super Meat Boy, an amazing game with incredible difficulty, but extreme care taken to ensure that the experience (often called "quality of life" in a game, is extremely high). In Duck Tales, the hit boxes are far too large for most things, but even this can be worked around. I'll leave the hit boxes alone for now, and get back to the point.
There is no reason to have to press down on the D-pad to activate the pogo stick. You only have to do this on the first bounce, then you can just hold B. This causes problems when you are pressing diagonal-down and the pogo stick disappears at the last minute causing you to take a hit. The only thing this does is make the game worse, if you think this adds challenge or difficulty...not sure what to say. They could have used controls similar to Castle of Illusion, just hit B in the air to start the pogo. Instead they copied Commander Keen, and the game is worse for it.
If B actually did something in the air, I could see the need to press down. But it doesn't. If B made you run, like in Super Mario, then this would make sense. But it doesn't. Again, you have to press an extra button for no reason.
I like my difficulty to come from level design, insane challenges, and precision timing. Not much of that here.
This problem is easily fixable if playing on a PC emulator, but it is a little complicated. You have to map the down arrow on your keyboard to the down arrow for your emulator, then, using Joy 2 Key assign both the down arrow on your d-pad and the B button to also activate the down arrow on the keyboard. If you did it correctly, you should be able to bounce without ever pressing down on the d-pad. This isn't without one small change: if your pogo stick misses a ledge, but only slightly, Scrooge will stick to the ledge and be ducking down. Not a huge deal.
Before you say this is cheating, just be aware that in the speedrunning/highscore community choice of controller, monitor, button mapping, control configs, etc. are all perfectly legal and fine. I consider this customizing the controls, but you might not. If you like how the game is now, then by all means, just ignore this topic. If you've ever been frustrated at the pogo stick disappearing milliseconds before you make contact with thr ground, however, then you might want to try out this trick.
If you don't like this setup, however, this is another option if you have some trigger buttons. It's much easier to activate the pogo if you map the right trigger to down as well. Now you can't say there is an advantage in mapping two buttons to the same button, and you are firmly in the realm of customizing the controls. The major downside is, of course, having to play on an emulator and not being able to use your cartridge.
It appears that the creators of the remastered version also agree with me, by the way, as it appears you do not have to press down in the new version to activate the pogo stick.
In the end, Duck Tales is still an amazing game.