Spotify redownloading somgs

[Addthissetting]

I have a usb hard drive and a ssd. The ssd is the main storage device, but doesn';t have a lot of space. i have about 500 songs downloaded, which would take up more space on the ssd than i am comfortable giving. occasionally the hard drive gets disconnected, so spotify decides to download everything to the ssd. this isn't too bad, but when i plug in the hard drive again, and even go into settings and tell spotify to download into the hard drive's spotify folder, it decides to redownload things that are already there. The 500 songs are already in that folder, but spotify decides it needs to overwrite every file there, which with 8 megabit per second download can be a big problem for me and my entire family (about a hour of downloading at full bandwidth, no download speed limitations, so full throttle or nothing). In effect i either have to not download songs, wait 10 years and waste 4 gigs on my ssd (when the hard drive is already more than fast enough for spotify music), re download 500 songs to my hard drive every time it gets disconnected or just not download songs on my pc anymore.

An incredibly easy solution would be the ability to get spotify to scan a location for songs already downloaded, but i do not see this anywhere in the settings. Either that or it should automatically scan for songs when the download location is changed.