This is very recent:

We’re continuing work on the Drive SDK. You can expect further performance upgrades that will roll out across all our apps simultaneously. This new SDK will also be the foundation for our eagerly anticipated Linux app. It will give us the building blocks to improve compatibility, drive faster innovation, and expand Proton Drive to more platforms.

https://proton.me/blog/proton-2025-autumn-roadmaps

https://proton.me/blog/proton-drive-sdk-preview