Shuffle Algorithm

[EotS]

I'd like to see if I can get some insight into the shuffle algorithm in Poweramp.

 

I've got 64GB of music on my phone, and from that library I've built a 98 hour playlist of about 1500 songs.  This is the way I like it, because I can almost never hear the same song over weeks or months if the shuffle is doing its job.

 

But what I'm finding with Poweramp shuffle is that I'm hearing a subset of that playlist repeating songs too often.  Now, that could be because I often queue a certain song here and there, and the algorithm starts over when I do.  Sometimes I wind up starting at 1 of 1500 again for one reason or another.

 

Is it built to work well with such long playlists?  And could there be a way to get it to stop starting at song 1 everytime I do something to get out of the playlist?