Ludwig I'm not in your league of disciplined maintenance nor ride in such rarefied clean atmospheres but am impressed by those pristine used teeth. In past when cycles were main means of travel in poor ole England fellas kept one chain in melted graphited grease til 1st one slung it out then switched em. Same with tires moving front to back. I am a bit confused though by your views, ie: why are both sets of teeth bright silvery, ie: not darker oxidized raw steel?
I tired 520 teeth on two cycles my modern 70hp/365 lb appliance vtwin and my Cdo clunker Peel that was both lighter and distinctly faster especially above 70 where hp comes into play over torque. I could feel the extra response in both of them both on throttle and flickabilty but so slight was not worth it after I saw how quick the front sprocket teeth fanned over and rear teeth turned to humps. Even if you can get extended life by constantly rotating chains, [very good on you] the 520 chains I ran had riveted master links so extra reason for my lazy man attitude not to rotate chains but to just stick with 530 size.
I did have one horrific event d/t new 520 Obsolete-ring chain that I'd set on loose side to creep up on full tension during initial engine run in. I hit a bump that compressed suspension enough to put enough slack in the STIFF chain it kinked up to miss teeth valley and rode up on the top of the rear teeth which so shorted its tension it felt like I was kicked in the ass by the shocks bottoming out. Of course I stopped to check to see full kink remained in chain run even with some tension in it. UGHHhh. This jerked the snot out of the tranny shafts, bent unknown, so AMC bushes dissolved in a few hundred more miles and gave clutch wobble that threw & chewed up a belt 100 miles from home. I switched to X-ring on Peel after that to use up rest of rear teeth but she had over rev event soon after so only got 2000 miles more mils use w/o touchy tire spin and front lifting power so decided in order to dice with new Duci 1098's better up the engine side of her. Peel will use up the left over 520 X-ring and Al rear teeth for easy break in then sticking with 530 chain and steel teeth ring. I checked Peel's new hub construction to see she can clear 530 x chain with 130 rear tire.
That day was one of my most mixed emotional daze on early Peel still only 2/3's iso linked, rump and head, sans breast control. Sick at stomach d/t the severe damaging loads and beat down teeth, so could not give full throttle or chain slipped in grinding sound, but still so spunky I pulled into a mixed bike gathering of many dozens and yelled out HEY who's the hot shot's here I've need to find this things pecking order. Most everyone pointed to two fella's, one on a Ducati 900 something and another on Triumph Speed triple. Dcuati dude couldn't or wouldn't keep up so became a hour long dual with the Triple guy in sparing joys that proved Peel could out handle it in tights but could not keep up on climbing straights d/t chain slip above the ton. That was on his home route road to boot all new to me.
Peel only got mid 30 mpg at these rates which led to another horrific event that should of killed me on any other bike, there was only 4-ish gallon left in IS tank near end of our games and I was letting him lead d/t not knowing the route, so on one decending sharp decreasing radius I tripped Peel down to begin my pass after the turn into down hill straight but the gas slosh did not keep up with the direction change so hit mid hi side out of there Peel jerked opposite direction mid flight so instead of landing aligned with path we ended up over 50 mph aim straight for the railing, so had to snatch rear out into another low side that hi sided back in line but couldn't catch back up d/t the chain slip. We hi fived in adrenalized joy and parted ways.
Shortly after, solo returning home one of the most extreme handling challenges I had occurred but no one would believe it. Checking with locals later was told No One But NO One ever got out of the Truck Gravel Trap w/o a crane of bull dozer, not hill climbing 4wd's or dirt bikes or ATV's in bottomless pit of polished pea gravel. I was so hi from the prior flings I just shot out into it at 45 mph it thinking it would be like my Gravel paths but instead got stuck about 3 bike length into it with 50 yd before a spot seen to get back to terra firma. Took some minutes that felt like dog padding in water and thank goodness the chain didn't slip on such low-no traction, as also told very illegal and all people drunk or not got jailed and vehicles impounded. I will be back on it for sure but with video and way lower air pressure.