The idea of Folgezettel (wich gives you the tree-like structure) is not something that is really needed for a so-called zettelkasten. You are refering to a method that Niklas Luhmann started to use, mainly based on the physical properties of his implementation (a physical zettelkasten) - it was easier for him to organize and find related notes in that way, but - and this is an often overlooked information - in his later days he prefered cross-referencing and switched his method more and more.
The ability of the concept of Folgezettel, to show trail of thoughts / arguments can be also done with “normal” links. It can be done through meta-data, and it can be done in naming-conventions for files and most likely many other ways.
To say that a tool is or isnt a zettelkasten based on the missing feature of a very specific way to link, that even his creator started to abondon in his later years is - well, misleading.
But this is a debate that was done dozen of times in many different forums, so i wont add much value here - but back to your main-issue:
To visualize a tree like structure, it might be possible to use mind-maps (there is a plugin that rendered them) - if its more about seperating different lines of thoughts - its possible to implement the naming convention in the file name (so in the file-explorer it will show you the hierarchy).
Beside this, there is really not much difference between a folgezettel and a cross-reference. The link itself is just a link. The underlying structure is done through other means (note naming).
Overall i dont think there is much to gain with trying to implement a special way to link, but there might be other use-cases where this is more interesting.
Personally i think something like weighted links might be interesting to test out
(like a link is given some number that indicates his strength / importance) - this way it would be possible to differentiate between different types of links.
But i doubt there is much to gain overall from this kind of system.