You have to remember the only safe way to get IVS working with either Dahua or Hikvision is to get a NVR from the same supplier. And even then you’ll run into problems as seen in numerous threads, because the NVR still requires you to configure some things directly on the camera. Not always clear what those things are, though. I don’t think
Blue Iris supports IVS events either.
I’d be really happy if you get Synology to add IVS support but I wouldn’t hold my breath, since it seems to be specific for Dahua and Hikvision. All in all, as long as you don’t have to get the expensive camera licenses, I think Surevillance Station offers great value for money.