System memory bloat when syncing large playlists

[Hosfordmc]

I usually keep about 20,000 tracks on my 6s and iPad Air. I’ve always been able to do this with a 128gb IOS device along with my usual array of apps and have between 9 and 11gb of free space leftover. I did an erase and restore on the second beta of IOS 11.1 and when I tried to sync I maxed out my storage and noticed that System had gone from about 6.5gb prior to the sync to 18gb. I loaded the third beta yesterday tried the sync again and got the exact same result. I submitted feedback to Apple covering this, but does anyone know of something that might actually help and what all that extra space taken up by System actually is? Is there some kind or log file that normally gets recycled during a sync that isn’t getting recycled and is just growing and sitting there? I’ve never had any problem like this before and I’ve been using the iPhone since the 3GS.