Yes, Unleashed supports UAPSD/WMM, and by default the DTIM is 2.
You may wish to issue a CLI command from your Master AP for "Spectralink Mode" which will
adjust DTIM=2, BSS-minrate = 5.5, RTS/CTS protection mode enabled.
See KBA-5875: Unleashed Configuring DTIM on Unleashed APs.
https://support.ruckuswireless.com/answers/000005875