Maybe try something like rclone instead, I think they added support for Proton Drive in one of the recent versions.
Proton
Proton new family
I've heard of rclone, and did see that they support Proton Drive, but it's just hard for me to trust a translation layer like that. I know emulating their program is also not ideal.
No proton drive Linux client is the only thing keeping me from buying in to Proton ecosystem. That said, I wouldn’t trust a translation layer for the stability that I would need to keep my data from corrupting or other issues
Yeah, this is my concern as well. Not just the additional chance of data corruption, but the extra layer that you have to trust. I just tried setting up a Proxmox VM running Windows and mapping the Proton Drive client to a NAS file share (hoping all my devices could see that file share and sync to it, then Proton Drive would sync everything to their servers), but you can't map network drives apparently. RIP.