Without this feature, Proton Drive is just sitting unused for me.

We need it, it is mandatory.

Mandatory.

Without it, protondrive is useless to me.

A deal breaker for user adoption.
At least provide an API so the community can build the necessary tools.

Having a dedicated Linux client rather than having to try and cobble together a solution is a must,

The obvious way to implement this is similar to the DropBox client where it loads when you log in to your computer and monitors a specified folder. While this is a good option for people who are not technically inclined, I would also see it able to load during boot as a background service to provide a WebDAV mount for seamless desktop integration.

Understandable for businesses in that you prioritize Windows and Mac clients, but for privacy Linux is a must. It just needs to sync a local folder to Proton Drive

As a Linux user forced to use windows and iOS at work, this capability is vital to me. If I cannot seamlessly sync my data from my Linux computer, I will probably stay with my current favourite, which does offer a Linux client.

Without a file system sync client, ala Nextcloud, Proton Drive isn't very useful for me.

Come on.... All this talk of privacy yet you only serve platforms with suspected backdoor(s). Internxt is an alternative with Linux support - still a little buggy at times but very usable (TIP: Sync is much faster and reliable than upload/download). A 2TB tier cost about the same as Proton Drive's 500GB. Free tier get you 10GB - very respectable.

It would be really great to have it. As you said you have been working on the LHC. They use Linux actively to do science, it is strange that you don't want to provide your colleges with such a great piece of software

Linux support is the only thing I care about when looking for a service of this type.

This is the only reason why I don't use Proton Drive. I made an account here solely for this request.

Proton's focus on security attracts many Linux users. It would be very popular as a cloud storage provider if they just let us use it.

Something working like Insync

Ubuntu distros tend to offer "Online Account" to hook up with. Like Google, Nextcloud, Microsoft, etc.

It would be amazing if Proton was one of those online accounts. I think it would help spread the Proton brand and make life nicer for Linux users.

Currently Google/Microsoft don't really offer amazing Linux support. So good Linux support may go a long way!

In a perfect world it would be just as seamless as One Drive on Windows or iCloud on Macs.

An app would be nice, but an API that rclone could use would be absolutely fine, and much faster for the Proton team to code.

Currently Drive is almost unusable with failed downloads, uploads, and the inability to check which files have failed and retry automatically.

What we need is a simple way to sync local folders with proton drive. GUI are generally cumbersome and useless, CLI are the best as the more efficient and flexible way for that purpose.
ProtonDrive is simply useless without this functionality...

Or at least an API, so we can develop extensions for existing tools like rclone (or create applications).

Would love to have this feature included.

this is required, i'm a linux fedora 36 user and love the ability to use cryptomator with my cloud storage like i do on filen io + cryptomator