Has anyone installed a gravity recirculation loop with a Boilermate?

I have a 40 gallon boilermate that has the dcw inlet on the bottom and the dhw comes off the top. The only other connections are the supply and return to the boiler.

I want to add a return loop from the farthest fixture to the boilermate. I am assuming I would "T" into the dcw supply at the bottom of the boilermate, with a check valve to prevent cold water from traveling along this return loop.

Should there also be a check valve on the dcw line to prevent warm/hot water from migrating into the cold water line?

Any advice is appreciated...I just am not interested in a solution that requires a pump, please.