Rejected

Push levels for fuel and tires

It would need a lot of precious dev time, as the whole tyre temperature system has to be rewritten and a whole new reason not to just set acc/braking push at max and leave it there needs to be found and written, a lot of effort put into getting the balance right, another selector occupying scarce screen real estate on phones is needed and it'd reduce usability of the UI and all that for what real gain exactly?

If running the wrong tyre temp would have much more severe penalties, more severe situational driver mistakes are introduced and/or design would require compromises resulting in situations like engine temp becoming an issue in a race that might lead to failure, then the matter would be different and much more detailed selection differing between pushing/working components and splitting it from how aggressive the driving is would make sense, but as it currently stands just running the tyres in optimal, if possible, while pushing as best as someone is able to and fueling the stint accordingly does the job nicely.

I can see a use for tactics playing weight and performance against each other during a given stint, but I fail to see a strong connection to strategy. But perhaps a misunderstanding, as I don't get the overfueling part of the OP as overfueling, as well as underfueling, a stint is a mistake and never a requirement.
Or is it born out of the common misunderstanding of what is set up in this game? What is set up is the fuel amount in litres and not the given laps, those are a mere estimate of the range that this selected amount of fuel might give, based on the practice lap consumption, but it will be more or less accurate given the actual factors present in the race (as well as some outside like level of CD). Those laps are a convenience, but it's up to the manager to calculate and set the exact amount of litres required for a given stint.