I rely heavily on the ability to freely adjust buffer settings within an open working session; I need lower buffer settings to record new tracks, and often much higher buffers to mix/master. My workflow involves mixing as I go along, and Pro Tools on a Mac (with the UAD Apollo) allowed me to do this for years. Pro Tools 12.4 on a PC running Windows 7 Pro 64-bit requires a complete quitting of Pro Tools (not even just the session) in order to recognize a buffer setting change. Not being able to change buffer settings without entirely closing out of Pro Tools is a massive impediment to my workflow efficiency.
UAD says this is something Avid could fix w/ a software update.
I would think that if Avid can enable active buffer adjustment with Avid audio hardware and other third party audio hardware on a PC (apparently Line6 and Presonus for example), it would be easy for Avid to also recognize buffer setting changes from the UAD Apollo console without requiring a complete shut-down and restart of Pro Tools every time.
PLEASE release an update to Pro Tools that fixes this issue.