If PulseAudio 8 is added into Rasplex we would be able to have Bluetooth speaker support.
I just recently spent many hours setting up Bluetooth speaker support in Raspbian and ended up getting it to work with PulseAudio 8.
Please consider adding into the next Rasplex build, finally we can have Bluetooth audio. 
Done, in next release using built in BT on RPi3, you will need a BT 4.x dongle for all other RPi’s.
Regards
That’s great news!
I imagine this should make a lot of people happy, bluetooth audio using (PulseAudio 8) is working really well in Raspbian, it would be great to make everything fully bluetooth.
The 3.5mm cable to my speaker sometimes makes a buzzing noise which doesn’t happen when using Bluetooth. 
Cheers