When you say "playtime", I think you're referring to how long it can stay on-station. So that's endurance, ie, number of hours it can stay up in the air.
Nope.
When you prepare a mission for a fighter, you have to give him a zone to play, a point to enter in this zone and a point to flight out. From the take-off to the enter point you have ingress, from the out point to the landing you have egress.
What I refer to playtime is the usefull time in the zone not the ingress or the egress time useless.
Chinese will have for example a huge advantage over US If f-35 have to come from GUAM or from the Phillipines. KC tanker can help to mitigate this problem of course but not totally by far.
For example IF US choose to have 2 F-35 over taïwan all the time during one month coming from Phillipines
That mean that they have to organize enough flight for 720 x 2 hours.
Flight from Phillipines is 40 min (600 km at 900 km/h), return the same, and I take one hour on station still at 900 km/h.
The playtime is 1 hour not 2h20.
And one such flight is 1/6 that a F-35A is able to flight per month today. To make such a mission with the actual avaibility of the F-35A you need 240 f-35A, not less.
Of course this is impossible because you also need KC tankers at each flight.
That's why I say that permanent aerial superiority is impossible over taïwan for the current block3F without a new engine. Permanent aerial superiority can not be obtain with F-35A. The only job that can be given to F-35A is SEAD/DEAD or RECO missions.