Dave, I just added one steel plate to the clutch pack and made a longer pushrod to get the adjustment right, and it made a world of difference!
I was getting a little slipping when hitting it to pass or shifting hard. Now it is much more solid. One clutch plate, a short piece of rod and finally broke down and installed a new gasket. A cheap fix, and it worked.

The factory service manual specifies a wear limit of 5.070” over 21 pins (center-to-center).  It’s pretty hard to measure that right to the gnats behind so I rounded to the nearest .005” increment.  Here are the results of pin measurements.
New 2016 chain:      4.990”
Chain #1:            5.005”
Chain #2:            5.010”
Chain #3:            5.010”
Chain #4:            5.010”
Chain #5:            5.000”
Chain #6:            5.005”
As you can see, none of these even come close to the wear limit.  Either I’m awfully lucky and randomly got a whole bunch of perfectly good $130 cam chains from engines that all had almost zero mileage….or…..the chains don’t wear out very fast.

3/17/22 Measured original OEM chain after logging about 23,500 hard miles.  It (chain #7) was 5.010”.  

Results for sprocket to sprocket are as follows.

New 2016 chain:      10.290”
Chain #1:            10.310”
Chain #2:            10.330”
Chain #3:            10.320”
Chain #4:            10.340”
Chain #5:            10.310”
Chain #6:            10.335”

If you consider that the factory wear limit on the pin measurement is about .080” over a brand new chain, and then look at how much the sprocket to sprocket measurement varies new vs old, things still look rosy for the used chains.  Worst case (chain #4) is only .050” greater than a brand new chain.

3/17/22.  Measured original OEM chain after logging 23,500 hard miles.  Chain #7 was 10.343”.

Here’s another shot.  You can see the rear guide’s get up & go got up & went.  I contend the problem most lies in the rear chain follower/guide.

The jack bolt installed in the head rectifies the problem by restoring the arc of the follower.  It allows the tensioner to maintain correct extension (12mm or less)), and in doing so, keeps the drive side of the chain well away from the slack side.

Mike, GREAT WORK!!! When I changed my chain at 80k I could not see any wear on the old one in slop or twist. Looked at the follower but saw no real wear on the surface so put it back in. I did not have a new one to compare it to. Now you have comfirmed my thoughts the follower is the culprit. The heat/expand - cool/shrink cycles combined with the pawl on the plunger is too much stress for it to take. Next time I have mine apart, I'll see if beefing-up the curve is possible.
When you are reassembling the engine try the old and new followers and compare the plunger extenson.
Your jack bolt looks good, but if the follower could be restored to stay at its stock curve I could leave the head on. I'll do a compression test and check oil usage at 150k, if things seem good I'll try to get to 200 before a rebuild.
I don't push hard any more (old) and my high gearing keeps me under 4 grand almost all the time. I'll shoot for 200k without spliting the cases, or pulling the jug or head.
I think the best thing to do is - AFTER BREAK - IN - remove the pawl and put a spacer behind the plunger with 1 - 2mm movement allowed. Without the heat/cool cycles stressing the follower it should retain it's shape and allow the chain to run it's life (100k+ miles ) without the plunger blowing up the primary case.

When I removed mine I was surprised at the flexibility of the system, (read rear guide.)

As stated before I removed the pawl spring and restricted the rearward movement of the plunger.

We can only speculate about- what if Suzuki had done what every other manufacturer does, i.e. a spring loaded adjustable plunger at the rear of the cylinder.

How easy is it to remove the rear guide with the cylinder in place?