I am using Konqueror to browse files in my phone through ssh like this:
Of course ip address should be changed.
It should ask for password and if public keys are set, it should show contents of phone right away. If DHCP is giving always same ip address to Jolla or it has been given hostname, then bookmark could be made and maybe some kind of icon could be added to KDE desktop which would open that location without work of browsing through bookmarks. Not sure about desktop icon, as i am using Konqueror in Window Maker.
In Windows i have used Filezilla, maybe others might find that useful. It needs little bit more work than Konqueror does. Winscp is another tool, if i remember right, but have not tried that.
If it is very important, that data does not change during transfer, then rsync or usb cable is better. I have seen file sizes changing, when moving video files from computer to another. They were still working perfect, but programs and such might not. I prefer rsync over usb, for three reasons:
Removing usb cable from charger and plugging it to computer needs some work.
It might not even work, as some has experienced.
When going to sleep and connecting charger to phone i will realize, that cable is still plugged to computer and i have to switch all lights back on...