Agreed to all those points, generally. Improvements are incremental, and the biggest gains are usually chosen first. Electronic control, easy
sharp tuning, automated functions and corrections for conditions are the big gains, while fuel distribution from MPFI is good, but smaller gains. Get what you can with the time, funds and skills you have.
Injection timing (fuel squirt end-point) is adjustable on most MPFI setups, but it is interesting that most OEMs and most performance tuners do the opposite of your description. This is of course tested while tuning, but depending on many factors from injector angle to spray pattern, injecting on a closed
valve promotes better fuel vaporization. Weird, as gut instinct first says to inject while the valve is open, right? But, even the newest systems try to enhance vaporization using stuff like dual-injection per-cycle or injection start at valve-close, in order to promote this "cooking" vaporization, and tighter-stream spray to the back of the valves, instead of the fog patterns we like to think are better.
For me, this is what makes tuning so much fun, as you don't really know what is going to work best until you get in there and try
it. A surprise in every box!