This is probably a non-issue, but before I create a setup with a neat wiring harness and button it all up, I thought I’d check..
I will be installing a Spartan V3 on a Honda K20A engine with an OEM Honda PRA ECU with different firmware (DocTronic) to allow the use of an external wideband for mixture control using an analog input.
All pretty straightforward stuff. (Sadly no possibility for CAN data/control.. 
)
I intend to piggy-back on the fuel pump trigger pin from the ECU to power on the wideband controller via a small relay. Again, all pretty normal.
The thing I was considering is that the ECU primes the fuel pump/system for about 2 seconds on each key-on before turning the pump off again until you start the engine.
Call me weird, but I don’t like consistently turning controllers on and off (fairly) rapidly every time you use them. Microcontroller boot glitches and all that sort of fun. 
So I was considering using a delayed-on relay as well. so it won’t put actual power to the wideband controller on the initial brief fuel pump prime, but only when the engine is actually started and the pump is running continuously for more than (for instance) 4 seconds.
That way the controller would always go through it’s full startup each time and not get turned off at least once during that time.
And yeah… Tradeoff is extra complexity here that could also break at some point, so it’s not all sunshine and roses. 
Probably overthinking it and just wiring it up ‘as is’ will be fine, but would like to see if there’s views on this.
