Help please, MacBook full!

Hi. There is advice online about moving an iTunes library to an external hard drive (I'd rather do this than set up a NAS) but my situation is complicated by the fact that I use a hiface USB adaptor and Pure Music to enable me to play hi-res music from my Macbook.
I use PM in memory mode so tracks are played from solid state RAM rather than the spinning disc. I also use "hog mode" and "less is more". Does anyone know if I'd be able to play music in this way if my iTunes library was stored on an external drive?
Any advice would be much appreciated, thanks.

Steve