Cross-platform DirectWrite (again)

[simoncozens]

Two years ago, @duncanmacmichael wrote:

Since the date of this proposal we've worked on porting DWrite features to DWriteCore and have been investigating the question of downlevel and cross-plat support outside of the Windows AppSDK. At the moment, DWriteCore is still Windows-only through the WinAppSDK, but our downlevel and cross-plat plans are still in motion despite no exact ETA. We still want to make this happen, but it's more complicated than we had anticipated. :)

What's the status now? I'm asking because I have a need for cross-platform and cross-shaping-engine font testing and debugging, which is currently very painful.