Backtesting the switch layouts.... The instrument panel cutouts plan on using the "Design1" programmer. This is a newish model, and so far SDS has posted the switching and fuses to-from the older style panel-mounted controller head. This looks consistent with what I understood when I did the switch layout. Looks like two electrical cables run from the control head back to the firewall one for the coil packs and one for the main harness. I'm guessing the panel switches are wired into those harnesses, and the harness will be custom built to fit my project. For purposes of the firewall arrangment, the single ECU dimensions are 3.875 x 8.5 x 1 inches, gold anodized, 6061T6, CNC'd billet. I'm doing double, so figure it at 2" tall. More electrical redundancy - this is a dual alternator system with a single battery. The Nuckolls design standard calls for sufficient redundancy to complete the planned flight. The SDS EFI system draws 1.5 amps and the fuel pumps draw 4.5 amps in normal ops (14 gph), 5.5 at the max expected draw (20 gph) = 5.5-6.5 a. Add 4a for the avionics = a total draw of 9.5 - 10.5 a. The PC680 battery has 16 amp hours, so I get 1.5 hours in which to notice the flashing lights and change to the back up alternator, cut high drain items (not many of those) and plan for a landing. This is an all electric engine in an airplane that "glides" at 150 mph, so the circle in which to find a safe landing is ~200 miles radius. I'm certainly safe, but the next step would be a move to a higher capacity b/u alternator - the Monkworkz ML-30z 30a permanent magnet, also using the vacuum pad. That will shift duration back to fuel remaining.