Freddy, I am going to answer you in one post:

F wrote:
the % found secrets is wrong.
- in contrary to the previous sections, this one is mostly one way what makes it difficult or impossible to go back to pick the missed money up (unless I am missing things).

Answer:
% secrets fixed. 
I have an idea of how to get  back but  as of now I just added a note to the first sign in my section.


F wrote:
Room 16899 (see pic).
Jack entered the room with a grey bat platform in the ULC. From previous actions I know that when Jack dies by slipping from that grey platform, he reappears in the LRC from the previous room. But when he dies in any other way except by coming from the room above with the ladder, he always reappears at the spot shown on the image. That looks weird and the solution to avoid game over is rather odd. Jack is not allowed to jump to the left by pressing the space bar and left arrow together (like on a solid floor). You need to jump up first (space bar) and only then the left button.
The starting position of the bird is in the URC. That gives a cheap death when Jack comes back from the room above.

Answer:
This is an odd behaviour indeed.  Fixed but hopefully I will later come up with more elegant solution.
Move the starting position of the bird.


F wrote:
Room 16699 is tough to execute. A trigger will activate a moving platform but since that T is invisible the odds are bad to get that platform corresponding with the zapper beam. Re-entering the room in the LRC helps, but that is where the cheap death is.

Answer:
No cheap death anymore.  Yes, this can take a lot of patience.  Best is to reenter the room and immediately run to the trigger.


F wrote:
Room 16499 (see pic).
The situation is this. When Jack starts moving to the left the waiting platform goes early down. Because he also has to consider where the bird is, it may go wrong. At it's best the platform moves without Jack to another room. That is because again and again a new platform appears. But the timing to take the platform is pretty tough.

Answer:
Fixed I hope


F wrote:
Room 16498 (see pic).
From the spot where Jack is, he may jump up the top of the gold wall. Continuing to the left leads to a cheap death.

Answer:
Fixed


F wrote:
Room 16298 deserves special attention. On pic 1 you see my Jack who just arrived in the room. It is clear that his task will be to get the key to open the door.
The second image shows that a platform and 3 pop-up blocks (with on/off-timer) did reveal. The 3 pop-ups need to create a safe way down but that is not easy at all because they got triggered at three different (invisible) places. Like it is now (on the pic) it is wrong. The moment that Jack jumps from blue to red, green disappears. Leaving the room and re-enter gives the opportunity to do a new effort. But going down to the bottom floor to leave the room is a problem on its own.
If Jack succeed in arriving at the blue door, then he may not have forgotten the key! In no way he is able to jump up the blocks. (HJS)

Answer:
I have tried activating the 3 pop-ups with different timing.  Never had any problem.  Usually I jump blue - red - wait a little - jump to green which appears while jumping.
Regarding going down to bottom floor via a squirrel jump?
There is a remedy now for key forgetting Jacks.


F wrote:
Room 16897
At the right side brings a grey sinking platform Jack down. Jumping on the gold bricks creates a HJS.

Answer:
Fixed

16697 In the room above, my Jack missed a jump and that is why he is hanging very dead near the left giant spider.
This room is cool because it gets complicated when the bird and the spider are moving together to the left (pic 1).


16897 My Jack did test the fixing of the HJS. A little bit later he died, reappeared in the upper right corner, used the sinking platform and jumped on the gold bricks. More rare but still a HJS.
What is the sense of the golden moving platform. Once Jack is on it (pic 2) it takes a lot of time to get on the grey one again. And is pretty hard!

16896 I like the puzzle about how to avoid death by the skeleton.

16298 Resuming. IMO the room feels too hard. Is it an idea to keep it like it is, but add a sign in the URC with some help in case of not fitting pop-up blocks? Something like: 're-entering the room may help in case of problems'.

Freddy wrote on 17.12.2023 at 18:05:33:


Added a sign to prevent a certain Belgian to repeat a certain jump
Regarding the golden moving platform:
Added a sign
There is also a sign just before jumping on the black platform, saying "Beware of illusions..."  Added a bit to that sign.
Increased the speed of the platform.

Freddy wrote on 17.12.2023 at 18:05:33:


Sign added.

brell wrote on 17.12.2023 at 18:27:14:

Well, my Jack completely missed his jump to the two right silver coins. See previous image.

To create comfort for my Jack I first prepared better saves in the three previous sections. That lead to a save 5 with perfect score and 16 lives left. That is much more than the previous 0 that became 6 by saving.

First of all I checked if awful things may happen during the sightseeing tour on the red platform. I was surprised that everywhere Jack committed suicide he reappeared in room 17099 at the spot where he jumped onto the red moving platform.

I found one single place where Jack could land alive and that was again that odd spot in room 16897 where you already added a skull and a sign. See pic 1. In the best case he uses the skull and continues to the right. Only the $ 250 from room 17099 stay out of reach.

But if Jack comes from Belgium he uses the skull and moves left to die in the gap. Then he reappears endlessly ... See pic 2. My free suggestion is: remove the sign and the skull and add an always active horizontal mini-zapper beam on top of the bricks.

Only then I did a new effort to reach the exit door. Since I built up knowledge during previous efforts, everything went smoothly. See pic 3.

Nice and very spectacular work, l !