This is my first post on this forum. I really took my time looking for similar threads but couldn't find them. I hope I am not double-posting.
To the point: Would it be too difficult (or maybe undesirable from the perspective of your design) to allow users to tag fields (simple, multi-line, etc.) and fieldsets with a class (good enough) or a list of classes (ideal)?
From my humble point of view, since you are already parsing some field types for tags like [id:xxx], |title:XXX or |err:XXX, it should not be hard to add parsing capabilities for one or more [class:XXX] or |class:XXX tags. I know I am evaluating this from the proverbial uninformed perspective, but I would like to read about your thoughts on this.
If you think this is doable, I would be willing to dedicate some time to look at your code (I think it is released under the GPL).
Thanks.
P.S.: From a fellow programmer: your product ROCKS; you are really good at this.