Based on the review posted, there is still no way to natively transfer files other than the web interface. The reviewer is a developer so he should know what he is talking about.
Thanks for the changelog... you're totally right about the software moving slow. Lots of UX changes, lots of battery improvements, but the only major feature added that I saw was handwriting recognition.
I get it isn't possible from an end user point of view to connect as mass storage. But I wonder if it might be possible with the hardware after modifications to the kernel configuration.
This is the only other method I've found: https://github.com/nick8325/remarkable-fs
You'd think scp would work also but I haven't found info on the subject and I don't own the RM1 to try.
edit: found someone's scp script: https://github.com/reHackable/scripts/blob/master/host/repus...
The changelog is public so you can see the rate of development if you're interested: https://support.remarkable.com/hc/en-us/articles/11500546010...