Span-level Custom Context/Metadata

Setup:
Elastic Cloud - Running version 8.6

I am looking for a way to add non-indexed metadata to an individual span instead of just on the transaction itself.
(See Metadata | APM User Guide [8.6] | Elastic)
In certain scenarios I want to be able to log larger json data for triaging issues, however the standard Span.Label is indexed and truncates the text after 1024 characters.
It would be possible to have a singular transaction with the custom content for each action, but that is not ideal since I could be dealing with multiple actions in each transaction and I would like to isolate the custom metadata to the span itself.