You are looking at a rare Sephardic Haggadah from the 4th century, CE. It is so rare that it was placed on Sefaria, the library you are looking at.
It is famous for several things, especially that word, kazayit, which nobody really knows the exact meaning of. The Haggadah talks about practices that are not followed or observed by Jews prior to it or after--or if they are, we don't understand the words, which is likely the problem.
I am Sephardic. Our language is Ladino, but it went through various revisions, and this is likely the cause of some of the problems for some of the puzzles caused with some of the vocabulary.
Kazayit is believed to mean "pea-sized" or perhaps, better yet the size of an olive. But then the question is are we being asked to dip the size of what which is kazayit? The bread? What is between the bread? What is mixed between the bread, as like a sandwich? And why?
There is the Hillel sandwich custom, which might have come from the 1st century according to tradition. But it is not dipped into the water nor is any portion taken from it to be eaten separately it. So the above that you quoted is curious but is definitely neither universal or understood.
I do not offer my opinions in my post. As you put it:
We may not agree on everything, but I enjoy your perspective.
I try never to offer my personal perspective. The perspective belongs to others, those of the JPS, SBL, friends of mine on the CBA, USCCB, and other academics I have worked with and have been my teachers.
I haven't anymore time, but I do hope you do take my advice that I think that there is more than sticking to one's personal views and trying to reinvent the wheel all the time. If you don't start with a foundation, you can't even learn to properly use the tools that are out there. I think you have a great mind and talent. You just need to discipline yourself to know that there are basic facts that are such-and-such and that these things are not as problematic or do not matter as much as you worry about.
In order to put you three-dimensional thinking to work, you need to start at a foundation. I hope you take my advice. You have the workings of a great educator.
Have a great holiday season or whatever, and a happy new year.