I don't think I need anything, but if I come across an obstacle or improvement I will speak.
So, I can do tire comparations, sauced and unsauced. I got slicks from various brands and ebay specials (that are proving as good as the other ones!); chassis adjustments are a roll distribution/slip angle management thing so I think with a read in servo angle from the Rx and front-rear shock stroke vs roll motion I can come up with something, will need a thermometer to read tyre temps; aero is easy, running ride height change vs speed; weight bias again is roll distribution so add that too; what is this "tweak" deviation you speak of?
Flex vs grip is easy to do once I have the provisions to use the telemetry on the car, same car (with everything the same between runs), record track conditions (temp, humidity) then remove or add flex and record the run. Should have different roll front to rear regarding the other runs. Also some adjustments like neutral roll axis make chassis flex less noticeable. So it's only the tweak deviation I don't know what is the others consider them on the TODO list.
Speaking of that list, a bit more of organization would help a great deal. @OP, how about creating a TODO list, with jobs assigned to each contributor?
@zerodefect: my intention with the telemetry is to read total voltage drop, easiest and a rough estimate but with more doing this we can draw some conclusions.