Love your pics. Been trying similar, but have yet to find an Elder platform at high enough elevation to get the headroom. All I have found and dug out, I hit the water level too soon, Best I've got allows only 3 block high headroom, but still makes a nice base. Put my bed in the middle and the Elder altar fire serves to allow it' usage.

Still hunting to get one I could go 5 block high and put smelter, charcoal oven and fire for the cauldron inside as well.