HDF5.NET and UWP sandboxing in Windows 10 (v1803)

Hi all! We are working on a UWP app that reads & writes HDF5 files (following the Data Exchange convention) using the HDF5.NET wrapper. Everything is working well within the user’s appdata / GUID folder, but we cannot write files outside of this - for example, we cannot write an HDF5 file and save it to the desktop or other arbitrary location.

I believe this is one of the sandboxing restrictions in UWP that has recently been “relaxed” in 1803, as we can now declare the broadfilesystemaccess capability and read/write other files into any arbitrary folder… the problem seems to trace back to the wrapped C++ call in HDF5.NET that actually does the file writing.
Currently we are using the precompiled binaries from HDF5.net and toying with the idea of building it from source (in order to give broadfilesystemaccess capabilities down to the C++ level. But, before we go down this road, I wanted to see if anybody has been able to successfully handshake NDF5.NET in to the UWP framework, circumventing the sandbox?