Please check your spam/bulk email – your support ticket was answered the day after your submitted it (Yahoo, hotmail, and quite a few others ALWAYS place PCDJ emails in spam/bulk email) .
Remember, after you initially import all songs into the master database ‘list’ — you can update DEX 3 with new songs by simply opening up DEX 3 and clicking on the folder where the songs are (in the folder they ‘live in’ directly). Once you click on the folder and you ‘see’ the songs load in the middle pane of the library they are added to the internal database and search cache (for good). This is what support wrote you back with. This is also why you want to nest your main music folders under ‘favorites” in DEX 3 for direct/easy access.
Unless Spotify changes their policy and permits commercial use, we aren’t going to take the (considerable) time to add support. SoundCloud Go+ is a good option now, and will get better.