The doubles forces of attractive gravitation is one of the most devastating arguments against RE.
Except it is all in your head, and has been repeatedly refuted.
You weren't even able to address basics of how forces on a rope act, so how do you hope to deal with gravity?
And of course, rather than link to the debate, where you were repeatedly refuted before you fled, you link to your compilation of dishonesty.
Complete demonstration, using FE and RE equations:
https://www.theflatearthsociety.org/forum/index.php?topic=30499.msg1905467#msg1905467
Yes, a complete demonstration that your hypothesis is wrong. YOU CANNOT HAVE DIFFERENT FORCES ON THE ROPE!
Person at one end pulls on the rope with a force of A, person a the other end pulls with B.
Thus A=-B.
This is the ONLY option.
You even reach effectively the same result in your analysis, you just label the forces differently.
Instead of A, you have A+B.
This is the force that the the person holding the rope at boat x is applying to the rope.
Instead of B, you have -A-B.
It isn't including twice the forces, it is just relabelling the forces.
It is the exact same setup, just with different labels, which again shows that the 2 forces are equal and opposite, and that you cannot have a situation like this where one person pulls on the rope with some force, and the person at the other end pulls with a different force (i.e. different in magnitude).
Your basic requirement is WRONG!
What you are doing is equivalent to starting with the hypothesis that 1=2 (or that 3/3 != 1), and then complaining that people show that that hypothesis is wrong.
Your paradox is based upon a blatant rejection of reality, where you complain that people show your rejection of reality is wrong.
Your false hypothesis can never happen if the net force on the rope is 0.
The only way to have it happen is if you go to a rope with mass which is accelerated. Then there is a net force on the rope and the rope moves.
Otherwise, there cannot be any net force on the rope and thus you must have A+B=0. There is no alternative.
If you wish to claim there is tell us how this extra force is magically applied to the rope?
Is it the person pulling on the rope applying a force of A+B?
Or do they only pull with a force of A, with the rope just magically getting the force of B from nothing at all?