A word of caution. I tried the pairing trick with another external gpu becuase someone here and also on reddit told me that this trick also works with another external gpu. I paired my gt 1030 with an rtx 3070ti and not only did I still get strained but now I am getting strained even with my 1030 and any other card I put in my system. I have tried every possible thing I could think of to fix it but I couldn't:
Reinstalling different versions of Windows, trying every dithering disabling app there is out there, installing dozens of different display drives, installing linux, flashing mb bios, flashing gpu vbios, ….
I would advise not using this trick with a system that is working for you plus atleast for me there were alot of downsides: some games kept crashing, some games you couldn't turn on dlss or raytracing, some games flickered …