It seems to me that there’s a really big missing feature of repeat groups: the ability to have a repeat group member that is a complex structure, and not just a text or graphic whose contents can be enumerated in advance.
E.g., suppose one member of a repeat group is a bar chart, with several elements (bars, labels). There’s no way to produce a set of variants in the repeat group because the whole chart isn’t a simple text or graphic object.
I realize this would be a big architectural change to XD, but I’m bringing up here in the hopes that some of the core team might hear about it.