Tire Gurus, what's going on with these Falkens?

https://imgur.com/a/IeqtfkX

These are Falken RT660s with kind of a mismatch of usage.  I got a flat a couple track days ago, so I bought two new tires and another wheel for the extra I was left with.  Going into this track day, the fronts had 8 sessions and one of the rears was 20 and the other 16.  Reading around has me thinking this looks like normal wear for RT660s and normal RT660 delamination on the one but would like some confirmation.  The majority of the uneven center wear happened on the tires' first three days at the track.  Once I noticed the wear, I added more negative camber to the rear and it seems to have slowed down or maybe even stopped.  The tire that looks to be delaminating was on the rear last time out and was moved to the front for this track day.  The delamination appeared after 4 sessions.  We were going counter clockwise so it would have been the tire taking the most abuse. 

Is there any issue with using tires at such different stages of usage?

Should I get the tires with the uneven wear flipped on the wheels and hopefully it will even out?

Should I be putting my spare on the corner that I expect to take the most abuse?

If I drive the same track and switch clockwise to counter every time, should I still be rotating my tires or will rotating track directions even the wear out?

Is there any benefit to rotating every session versus at lunch versus at the end of the day?

Any other sage advice?

It's a known issue with RT660s, some people have had good luck with returning them if it happens early enough:

https://grassrootsmotorsports.com/forum/grm/falken-rt660-visible-tread-splice-seam-delamination/207167/page1/

Is there any laterally uneven / "cone-shaped" wear? If not flipping them on the wheels won't help. Also, since these have a directional tread, flipping them on the wheels could cause them to draw any dirt or water toward the center of the tread instead of pushing it out, so that would be a bad idea on anything but a clean dry surface.

It looks like that RT660 may have just got way too hot. What model is your spare? If it's something that handles high heat better then running that on the corner that will take the most abuse could be a good idea. In any case you should have the spare ready to replace that tire.

If you're switching directions back and forth and the uneven wear is mostly lateral, then the change should even the wear out and there's no need to rotate.

Rotating every session should be huge overkill if you have a decent suspension setup, if there was actually a need to rotate that often, it would be a sign that you have to improve the suspension setup or tire choice so that there's less need to rotate. You should definitely not have to rotate tires during an event. On my Toyobaru I've found that rotating tires once per race season is sufficient with 200-300TW tires.

The center rib wear is pretty normal for performance tires. It looks like you're cooking them though - take a cool down lap every now and then, maybe spray then a bit between sessions if they're still warm before going out for your next session. The RF being destroyed on both edges makes me think it might be an alignment issue. To me that all looks like general tire advise, not a falken specific issue.

In reply to GameboyRMH :

The spare is another RT660.  Wear is pretty even other than the center rib.  I thought since they are directional but not asymmetrical, I could flip them then put them on the opposite side of the car and they would be rotating the correct direction.

I was having a pretty frustrating day.  I probably was overdriving and might have pushed it too hard.

In reply to czerka :

Yes you can take the tires off the wheels to flip them left to right.