Good call. Id make it a 20 or 30 minuite session, thats all. Id keep the current parc ferme rules tho, as theres some ammount of parts changed on a couple of cars for saftey reasons. Just look at Suzuka this year for McLaren with Hekki and STR-Ferarri:
McLaren Mercedes:
Car 01: RHS sidepod wing to floor mounting pin
Car 02: Nose and front wing assembly
LHS front upright
LHS front top and lower wishbone
LHS front pushrod
LHS front track rod
Steering rack
Steering column
Headrest
Forward floor
Floor assembly
Gearbox to engine bolts
Gearbox
LHS rear top and lower wishbone
LHS rear pushrod
LHS rear toelink
RHS rear brake duct wing
LHS front wheelnut assembly
Rear wing assembly
LHS Sidepod wing
Rear light
LHS rear wing to floor stay
LHS rear bodywork ¼ panel
RCS shroud
LHS rear wheel shroud and rim
STR Ferrari:
Car 11: RHS front corner
LHS front corner
Power steering assembly incl. sensors
Steering column
Nose and front wing assembly
Floor assembly incl. sensors
Plank
Side pod wing
LHS rear wishbone loom and HIU
Pitot sensor assembly
Car 12: RHS front corner
Steering column
Floor assembly
Plank
Beam wing
Side pod wing
RHS rear upper and lower wishbone
RHS rear track rod
RHS rear pullrod
RHS rear brake pipe
RHS rear suspension looms
RHS rear upright and driveshaft
RIS rear light cover
Rear light
RHS rear brake duct wing
RHS rear brake duct cover
Rear wing
Engine cover
Power steering assembly incl. sensors
RHS front wheel cover
Some teams only change one or two small things like a wiring loom or a mounting pin or mirror glass or a radio component. Then theres the brakes.