Pass a query parameter to a Power BI tile? (not filter parameter)

[JonathanGibbs]

I have a PowerBI report that uses a parameterised query in SQL Server (a tabular function). I can create a parameter in PowerBI and successfully pass its value to SQL Server by modifying the query in PowerBI using Advanced Editor. When I change the parameter within PowerBI and refresh, the incoming data changes. All good.

I want to use the report in a Power App. Can I expose this parameter to the embedded Power BI tile functionality in Power Apps?

I know I can parameterise a filter by manipulating the TileURL property, but that's not the question. It looks from this that a query parameter can be passed using the syntax rp:<paramname>=<paramvalue> but I can't get that to work in the TileURL.

Before anyone asks why do this - there's some  pretty heavy lifting going on in the query which is achieved much faster in TSQL before any filtering kicks in. And yes, I could get PowerApps to write the parameters to a utility table in the database before firing the PowerBI report, and use that within the query: but this is not ideal with multiple users.