I like the general idea of more flexibility for sure. A long time ago I had originally given the option of it just to look at designated folders instead of making copies and moving them. My biggest gripe with that is the potential of people moving files and then having to deal with that. I deal with that in my DJ software where it looks at one big music folder but if I move one song to a nested folder in that same folder to attempt to organize, I have to go in and map the file in the software which annoys me. But at the end of the day, if the user would like that and can deal with the repercussions of that then I don't see a problem with that being an option.
In general it does sound nicer to just have multiple folders selected and then it can just pull in whatever it sees, including if some are added into the folder later, I do like that.
The older version did have some sort of "foldering" type set up where it was basically saved searches but I definitely would like to expand on the better organizing within, including "Projects", I can see that being nice for when you start developing something and want to just have a separate section to easily navigate to.
As for the speed/lag, could you elaborate on that a little? I did notice importing large amounts of files on Windows seemed much slower than on my Mac which I could probably figure out. But do you mean like outside of that, like scrolling through the assets/searching as well? Just curious to help see, how many assets were in there when you see the lag/slowdown. I definitely didn't test enough with LARGE amounts of files so that would be worthwhile on my end to see. Otherwise yes, thumbnails for images would help, probably also making it toggleable to not show animated gifs or anything in the list.
Oh yea for Linux, I should be able to get an installer for that. Does the DMG not work on Linux? I thought for some reason that would work (sorry I have hardly ever used Linux).