Ok, we just discussed this with @AlanRynne and it’s a bit trickier to support this in Dynamo.
Dynamo does not support metadata in any Geometry classes, hence when converting a Brep→Dynamo or any other geometry for that matter, any userStrings and other metadata that was attached will be lost. Grasshopper has the option to “not convert” objects because it defers conversion to each node, while dynamo converts everything upon receive. This may not be doable, or may require some big changes on how Dynamo connector works to support it.
So in the meantime, I’d recommend you to go with the GH route. Here’s a simple Grasshopper script that extracts the userStrings and stores it in a separate key.
UserStringExtractionGH.gh (8.3 KB)
I hope this helps.