Works good most of the time.

OK

It does not save files which contains ".Net" in title

Just simply works!!!

It only allows me to download 3 videos per day, which seems insufficient to me.

What user who're having problems, there is a procedure you'll have to follow:
1) www.yourvideofile.org/support.html
2) Click on "Get Temporary Fix"
3) Follow the instructions and you should be good to go.

Extension is pretty good, but doesn't work for many YouTube videos.

Dishita, Version 21.3 worked flawlessly until of course, YT changed their code. With Version 24.1, the green download button doesn't appear anymore, has YT changed their code again?

It's a robust extension that should be usable forever after a single worked, but sometimes (perhaps for videos longer than 5 minutes), downloaded content can lose a segment of its beginning.