Yes we work only with Avycon and Axis for several years now since I've tried to steer us away from Hik and Dahua.
The control is limited tho. There is no API, that comes directly from Alfred who is an engineer there who gives the best and most advanced support to us from time to time.?
Since we don't use external control for these, I'm sorry I don't have more relevant info...... But I would say that their onvif support is solid and if you are simply controlling cameras, not playback, you should absolutely try sending IP onvif commands directly to the cameras not the nvr.
Beyond that, ask for Alfred ..? and if you do get any updated NVR control please let me know !
C
