Hi there - here to make one post here.
I have a Swann DVR that came with 6 cameras which I use in my shop. I have 2 extras that years later I decided to try and use at home with my Synology NAS. After reading this thread and trying to gain control of them I gave up and ordered another brand camera. Like an idiot I am I kept trying before the new camera arrived and can now use the Swann cameras without the Swann DVR.
I figured I'll share my experience in case it helps anyone.
I was able to see the cameras on my home network using the Homesafe Config Tool - but the admin page wasn't accessible from the url discovered, even after changing my computers ip to the same subnet.
The solution was to connect the cameras to the original NVR - when connected to the NVR there was an option (going from memory here) to turn off "private". That allowed them to be connected to without being connected to the NVR. This was the breakthrough for me. Presumably not possible if you don't have a Swann NVR handy but useful in my case and maybe yours.
Another thing to note is that the admin page that requires an antique browser so it can install the plugin. I didn't have any luck using internet explorer, but I did using edge and putting it in a compatibility mode. Skip that though and download Swann Security program for Windows (mac not tested). This is will give you all the same abilities as the web admin but without having to download the plugin that requires an old browser.
I did set a static IP on the cameras to match the network I was using it on when I had access to the configuration, but I'm pretty sure after you disable "private" it should be happy with being assigned an IP from DHCP of your router. If not, connect it to your computer directly and set your computers ip address within the range to match the cameras to get access.
I've been able to get full access as I'd hoped and to change the settings directly on the camera including removing any watermarks and timestamps.
Worth mentioning, the firmware on the cameras I'm using is V14.45.5.0_191204
Good luck!