My setup is kinda similar to your except I don't have a burner for the MLT. I rely on the HLT to heat up the wort if my strike temp is off or my temp drops enough that it needs a little kick. Here's how I plumbed mine using only one 3-way valve. Your way will def work and I personally like...
From left to right HLT - Mash Tun - Boil Kettle
I have burners on the HLT and BK with a HERMS Coil in the HLT.
The connection on the left kettle is the return through the coil in the HLT back out the top and into the mash tun. The top connection is off in that pic as it is the last part...
I'm always on this site and finally decided to stop being a bum and setup an account. Wanted to contribute a couple pics of my projects to see what you guys think. :mug: