^ this
As someone who just learned recently. I see no point in this. I don't even look at the tach to shift. I do glance at it when really going for it but only so I can not hit the limiter. My hand isnt on the shifter until I need to shift.
In any car with electronic accelerator pedals, you can run right into the limiter, and use the drop in torque to get out of the gear without unclutching, then clutch into the higher one
As for the topic: sure it's nice to have access to some of the ECU - but why aren't car electronics fully modular yet?
I'm mainly interested in this, because these days many new cars come with plenty of forward looking sensors, thermal, visual, radar. Logging those could replace an ugly dash cam. But getting access to those systems, and plugging in a hard disk? In a normal PC it wouldn't be an issue, but a car PC is sacred, and even interchangeable head units get rarer and rarer, while hard-mounted touch screens become the norm.
With electronics advancing at a much greater pace than the engineering of cars, replacing electronics for a car two to three times during ten to fifteen years of lifetime shouldn't be exceptional. Standardize hardware interfaces and form factors already! Allow the users to run their own software (within reason, I guess you want to have some safeguards built in)