Recirculator pump hot water
I believe that you could use that pump as you describe pumping through a dedicated return line. For reference, this is what I did for my house. I have 3 bathrooms, so I ran a 1/2" dedicated return line from each bathroom to a point near the hot water tank. At that point, I tied all the lines together and ran that line thru the smallest bronze pump I could buy that was for domestic water. On the discharge of the pump I installed a 1/4" orfice to limit the pumps flow and from there to the bottom of the tank. I use a timer to only run the pump at specific times. This set up has worked for 20+ years. One last thing, When running the dedicated line, make sure that you install an isolation valve and a check valve to stop any reverse flow.