Here's something else to look out for...walking through a spark. Not sure if it's a problem with MAME emulation or an actual bug in the code that would happen on arcade as well. Money shot is at about 0:25.

Youtube link - Walking Through a Blue Spark

Wow that was a while ago.

Well, I actually did later find the code responsible for this bug later when I was in development of DK Junior Remix so here's the explanation of what's going on!

There's a bug in DK Junior's code where there are 10 slots made available for the blue and yellow sparks in Mario's Hideout...
but the initialization code only sets the hitbox size for the first 8 slots.   Everything runs fine as long as there are never more than 8 sparks on the screen but as soon as a 9th or 10th spark gets assigned, any sparks in those two slots don't have any defined hitboxes.
You can still jump over them for points or smash them with fruit (if I recall) but you can walk right through them because they have a 0x0 hitbox.

Level 4 Springboard (Going the long way around, AKA Avoiding the Super Jump)

Not good for points, as this method takes time. I'd only use this if I didn't hit the initial super jump and if I am only aiming for a kill screen

I've tried it a few times in this video, and it seems to work consistently.

I get the same result on both those links.

Which makes sense I guess, since they are the same. 

If anyone from the MARP side needs technical help getting things up and running again, I'm happy to volunteer my expertise, whether it's with Python or SQL.

I'll mention it on the forum there.

If anyone from the MARP side needs technical help getting things up and running again, I'm happy to volunteer my expertise, whether it's with Python or SQL.