@EricG is right that a simple implementation of IBIS does not require typed links. There are four basic node types (issue/question, position/answer, pro/supporting argument, and con/attacking argument) and the link type is implied by the node type.
The only type of node that you couldn’t have, as @ardente implied, is a hybrid argument node that supports one position and attacks another. You would have to duplicate the argument into separate supporting and attacking nodes instead.
But @ardente is right that even with the limitation imposed by an implementation of IBIS without typed links, IBIS is still not necessarily hierarchical, since a position could respond to multiple issues, an argument could support (or attack, but not both support and attack) multiple positions, and an issue could question multiple positions and arguments.
So you don’t need the Argdown, Breadcrumbs, or Dataview plugins for a simple graphical IBIS implementation. You only need to tag each node/note with one of the four node types, and use the Style Pane in the Juggl plugin to style each node-type tag with a different icon and to style the links as directed edges.
When you’re building your issue-based information system, you just need to remember the IBIS rhetorical rules, which are well designed and summarized in the schematic diagram that @Ooker embedded in the original post above.
IBIS is a great basic set of node types for rationale structuring, but you can add more node types such as: a generic information node that provides extra information about another node, and a decision node that indicates that one of several positions about a decisional issue was chosen from among the others. (Both of these extra node types are in Compendium, which was the most famous IBIS software.) An evidence node type can be useful for attaching to argument nodes, since evidence is usefully distinguished from argument. I have found inspiration for other node types in the bCisive Online Editor, which has different sets of node types in its left panel, such as the “explore options” set, “test hypothesis” set, “analyze reasoning” set, “capture discussion” set (which is equivalent to IBIS), and “evaluate” set.
By the way, it is also helpful to have a set of tags that further indicate the epistemic status of your IBIS nodes, such as #unanswered or #needs-more-answers for issue/question nodes lacking sufficient responding positions, #needs-more-pros and #needs-more-cons for position/answer nodes lacking sufficient supporting or attacking arguments, and #needs-more-evidence for argument nodes lacking sufficient evidence.