It would be nice, to have bigger thumbnails.
In version 18.104.22.168 the maximum size of the thumbnails is 240 (px?).
When the thumbnail mode is selected on the viewer tab, the size can be controlled with the "Preview size" slider between 95 and 240. (480 or 720 size can not be selected, but it would be great)
If the host has multiple monitors (2, or even worse, 3), the maximum thumbnail size of 240 is for me too small.
It's hard to see, if there are some error messages on the remote host, or something gone wrong, especially when the viewer runs on a 4K monitor.
I found the corresponding option in the config_4.xml file:
but changeing it to a bigger value in a text editor, causes the viewer to crash, when it's started.
(The thumbnail frames are displayed larger, but the remote desktop image is not, the viewer hangs.)