In the Dimension of Death there's a ladder in one of the halls that goes across (not up & down) and on that ladder there's a chest. Is there a way to get to it? If so....how?

I have no idea. There are a lot of walkthroughs online and also YouTube videos - you would think that it would be mentioned in one of them if getting the chest is a possibility. I am sure you have looked at most or all of these, though.

I also posted on the KQ group on Facebook, and one of the other members said: Back flipping up a stepped corner and walking across the top of the wall iirc.

I want to see if I can find a video on Youtube to see if I can sometime get this. In some spare time, I'm replaying the game to make saved game files for my collection (I keep them on an account on mega.nz, I did this for all Nancy games, and the four-chapter Cognition game)

I think this game is underrated. It is a good one. I hope you can find a video on YouTube that shows how to get the chest.

I tried following those directions and couldn't get Connor up there....but I did find something I've never noticed before. You can actually BYPASS the bridge of Life if you play in God Mode and just fly/leap across the black river to the swamp portal

That's interesting.

I tried it just to see if it would work. I know a lot of people complain about this game, but it's one I love.

I loved this game when it came out, except for the totally unnecessary action sequences. I remember that the loading times were 7 (seven!) minutes back then.

Wow. I do remember some long loading times back when the game was first released, but I don't remember them being seven minutes. Playing the game now, though, certainly eliminates that particular issue.