Using Graphics adapter to overcome GPU max screen limit?

[WiredG]

I am currently running 5 screens on a dual GTX 1080 system, but one of the screens is not on because of the GPU max screen support limit.
I have searched around a bit and tried to find a solution to this problem, but no luck. I do however have a few solutions that might work.
1. Using a third GPU outside of the case. However this would not be practical.
2. Using an external graphics adapter, like this one: https://www.computersalg.dk/i/1007771/startech-com-usb-3-0-to-dvi?gclid=CjwKCAjw9-HZBRAwEiwAGw0QcTCfh8HBHTT-ZQAtbeqCyC27vwaAg0SsVIf2m-MPt0TLB3IEjhiNgxoC1vcQAvD_BwE&gclsrc=aw.ds#specsarea
 

The second option seems the most attractive solution for me, but I am not sure that it will work. Does it render the screen separately or does it count as a screen for the GPU. I am not concerned with the resolution, as i will just be using the fifth screen for media.
If you suggest other hardware please find a link to something in Denmark, Sweeden, Norway, Germany or UK, because of tax policies in Denmark

Computer Specs:
GTX 1080 x2(SLI)
Ryzen 1700x
64GB corsair ram
MSI x370 gaming pro (Not carbon)
Plenty of storage

Thanks in advance

[Electronics Wizardy]

second option will work, but normally there pretty laggy.

 

You can also add anouther gpu in your system like a 1x gt 710..

[WiredG]

How laggy are we talking?

Is it above 30fps?