If in fact tires will be monitored...here are some ideas...
1. Every competitor is supplied one new set of tires at the track(purchased)and Toyo supplies free mounting and balancing. During the mounting and balancing tech weighs and marks all wheel and tires.
2. Every competitor has the option to purchase a 2nd set OR bring a mounted set that will be checked for a minimum tread depth (3/32?)and also weighed and marked.
3. If 2 sets are purchased, either set may be used in any session(qual, qual race 1 and 2, Championship race)...practice or testing excluded. Those sets may NOT be mixed!
4. If only 1 set of new tires is purchased...that set MUST be run in the Championship race(with the option of any other session as well). Scrubs or new tires not mounted at the track(provided by the competitor) can only be run up to the Championship race.
I think the above gives everyone an equal opportunity to manage their tires without an excuse if they flat spot any! I can see a few possible exceptions to this(no fault incidents)...which should be considered.
Again, as someone mention, the above would be only if a competitor wishes to be eligible for contingency's and or podium awards. If they choose not to purchase new tires they can run what they brung but will not receive(be skipped) any money or awards.