sp_describe_first_result_set with json columns

I'm working on an analyzer that accepts a SQL Server query and returns information about all columns in the first result set - until for clause is used, this is pretty straightforward with sp_describe_first_result_set. However, the queries I expect heavily use for json and sp_describe_first_result_set reports columns using this clause (correctly) as nvarchar. I've tried rolling my parser with SqlScriptDOM, but parsing got complicated fast. I've also toyed with restructuring the inner queries via said parser so sp_describe_first_result_set could be run against them (basically extracting them to be top-level). This approach also hit the complexity wall. Is there any reasonable way to achieve this? When working in JetBrains' IDEs, I've checked that their built-in SQL query editor has this functionality, as hovering over a star in an inner query shows the exact columns to be selected in a tooltip.