We currently have no drain. Only two holes so far - 1 for the element, the other for the
brewhardware.com sightglass w/ temp probe threads.
Post boil we chill with an immersion chiller, then use an autosiphon to rack into primary. The stand is built purposely
just high enough to do this.
The highest part in there is the element. I have it as low as you can go using Kal's setup - the junction box almost touches the ground. I also adjusted the legs on the basket for maybe only 3mm of clearance from it. That gives somewhere around 3.5 gallons of dead space. Quite a bit, but we are going to try a 5.5gal AG batch on Sunday anyways. Wish us luck.
The rounded portion of the kettle ends only maybe 1/2" up the side. There is plenty of room to put in a dip tube without a height issue. As far as a street elbow at the 5 gallon mark, I think you'd run into clearance issues between the basket and pot. It fits relatively tight. You'd need something really low profile, or to mount it below the 3 gallon mark.
If I did it again, I would put the thermocouple 90° or 180° from the element. I have to be careful when I lift because I'll catch a basket leg under the probe or element easily the way I have it now - maybe only a 15° window. I have marks on the two I align to prevent it.
If you recirculate, I'd think about putting the temp probe on the recirc line. You'd get great response.
I don't really see the need for CIP, although I do like the idea. Once we put the wort into primary, I just unplug the kettle and RTD, tip it over the washtub, and rinse it out. It's big, but not heavy, and Kal's mounting technique is very sturdy for those inevitable bumps. It takes maybe two minutes. Nothing burns to the bottom like with gas, so cleanup is stupid easy.
Recirculation is our next step. Right now the whole process is just so simple, and the beer is tasting great, so I'm in no rush to change it.