With the fittings 2" from the bottom of the kettle how deep did you have the basket made? Was 2" recommended by spike or was this your number. I've started conversation with spike just recently on a 20 gal kettle build with a ss mesh basket from arborfab.
My 15 gallon Spike kettle is:
19.4¨ Height
15.8¨ Diameter
The basket is:
15 3/4" Height (excluding the legs)
2 1/2" legs
18 1/4" Total Height
12 1/4" Diameter
When I actually measured the positions of the TC ports on the kettle and looked at the schematic/quote again I realized that they were measuring from the lip of the stepped bottom. Even then the centres of the TC ports are 2 1/4" not 2".
When I tried it with the basket on my first brew, the bottom rested on the element at the edge of the basket (the element slopes downward a bit so only touched on the edge). It also meant that the basket sits up about 1/8" too high and the lid touches it.
So I would recommend if you're getting a basket and kettle custom made that you make sure you and Spike are on the same page on the measurements. I had the basket ordered before the kettle so wasn't able to confirm the measurements on the kettle beforehand.
I might be a bit pissed that the measurements were off but in any case, I didn't like the basket because I think a lot of the recirculating wort simply passed out the sides and down. Also it limits the mash volume compared to the volume of the kettle. This one was not custom made, so you could get the diameter of the basket closer to the diameter of the kettle to remedy this a bit if needed.
Yesterday I did my first attempt at recirculating with a Wilser bag and a Brewhardware false bottom. This worked better than the basket. It fits better, allows higher max mash volume, easier to manage and gave me a 7% increase in efficiency (65% with the basket, 72% with the bag...very similar grain bill). No problems recirculating at all with a 0.040" mill gap and conditioned grain before milling. I didn't recirc at full blast but probably ~1/3 of the way open on the ball valve which was more than a trickle and gave decent flow. Sticking with this method from now on.