This is already present in a way. Have a look at the "Show downloaded files" functionality. Unfortunately this only works for files. But you can create multiple instances of the same host using different directories, and label them accordingly. I don't think any bookmarking feature is strictly necessary because of these functions, but you're more than welcome to try and implement it yourself.
This is related to issue #25 I believe. It's definitely something that would be very useful, but because of time constraints I haven't been able to implement it myself.
Hello, I am sorry if this is not the right place. I have two feature requests.