I know that these tags come from a preset. The problem is that the tagging scheme has neither been discussed nor documented, but is being pushed forward by a single user. Due to the missing documentation and discussion, there is no and will be no support from any tool.

In fact I can't see anything complicated with the signs you linked. All fit in the common tagging scheme nicely - as said, with an extension to mark the sign as roundabout-style.

It's impossible to discuss this in a changeset comment, I propose to move it to a thread in the community forum.
We might find that we actually need a new scheme, but then it has been discussed and a documentation can be written.
