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If you turn on the cold tap from that faucet, would you get hot water out?

Well, it's not going to push it into the cold water pipe until it's reasonably cool, so while it's possible that there might be some warm water immediately after opening the cold faucet, it's not going to be significant. I supposed that the valve installed could potentially fail open, though.

The way this is normally done when putting in a hot water recirc system at build time is that there is a separate return line for the hot water. The return is apparently also sometimes used in the heating system as radiant heating, which, if a separate system, would be circulated anyway.
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Bitt Faulk