Regarding testing...
The more you test AND give a treat, the greater the likelihood that Jazzy will get used the process. Give your kitty a reward every time you test. I would even suggest taking Jazzy to the testing spot, play with his ears, and just give him a treat. The more the expectation that something good will happen with a test, the easier it gets. Also, it really depends on what your cat considers a treat. Mine was highly food motivated. There are members who would find brushing was a treat.
The reason the spot checks are so important is that Lantus dosing is based on the nadir (the lowest point in the cycle). Based on your curves, Jazzy's cycles have been pretty flat -- which is wonderful. However, you also don't want to miss a possible dose reduction.
There are differences between TR and SLGS. I'll do my best to give you a feel for how they differ. Both methods encourage getting an AMPS and PMPS and at least one additional test each cycle -- so a minimum 4 tests per day. Regardless of which approach you use, you need to have enough data to know when Lantus onset and nadir occur and how much duration your cat is getting.
- Tight Regulation (TR) Protocol: This is a research based approach for Lantus and Levemir that was published in a leading feline veterinary journal several years ago. It's strength is that it can get a considerable percentage of newly diagnosed cats into remission. It is aggressive. Once the depot is established, doses are evaluated every 3 days if nadirs are > 200 and every 5 days if in lower numbers. When using a human meter, dose reductions for a cat within a year of diagnosis are given when numbers drop below 50. You gradually work your way down to shooting any number above 50. For someone brand new to FD, the "post and ask for help" pre-shot number is 150. Because you can be dealing with lower numbers, more testing is often necessary. FWIW, many of us who work full time are able to still use this method. You cannot use TR if your cat is eating any form of dry food.
- Start Low Go Slow (SLGS): SLGS was developed here. It is an approach that is applicable to a broad range of insulin types, not just the depot insulins. There is no formal research that documents the utility of the approach but many cats have achieved remission using this method. There is also far greater flexibility. Dose reductions occur if numbers drop below 90. Doses are held for a week, you run a curve, and then decide if an increase is needed. One of the issues that I often see with SLGS is that people hold the doses for too long. The "post and ask for help" number for a new member is 200. Again, people seem far more reticent to start to shoot lower numbers.
It it's not evident, my personal preference is for TR. It's what I used with Gabby. I think the instructions are far better laid out. TR was first used by the Lantus group based in Germany and that's where the research data were collected. One of the members here brought the protocol to this group. I like the science behind it. However, the approach isn't for everyone.
So that's the general perspective. With Jazzy, you're seeing absolutely wonderful numbers. There are a couple of additional aspects to TR. A dose can also be reduced if your cat is in normal numbers for a week. The mid-cycle tests would tell you if Jazzy's dose should have been reduced because it looks like Jazzy could be very close to remission. With SLGS, you would have already been reducing -- you have a lot of numbers that are below 90.
As for the social norms here, it is obviously a big forum. We can't get to know everyone. Like Sue, I work during the week and my hours routinely exceed a 40 hour week. (I can't even remember when I worked 40 hours -- it's usually a lot more.) I'm sometimes able to check in during the day. By the time I get home, I'm totally exhausted from a day of Zoom and other activities. I'm guessing it's the same for many others. I've been around a whole let less since Covid since I work in healthcare and there's been a huge demand. I do try to be here during the weekends and sometimes in the early AM. Thus, the more you post, the more people get to know you. If you post in other people's threads, they will reciprocate -- and looking at other spreadsheets can be very informative as can reading a thread that seems to be related to your cat is also helpful. Like Sue suggesting, using eat "?" icon in your subject line or indicating if you have a question or problem will get attention. Experienced members and the moderators look for that information since everyone's time is limited.
You're responsible for someone else's beloved cat...and heaven help us all if you're the one giving the advice and it's not right...that's why we call it a 'FORUM'...hoping lots of experienced people can weigh in and give opinions and advice - it's not the law or the gospel...it's advice...and it's hopefully taken that way - it's up to every member here to READ the stickies...LEARN from other's condos and comments...and yep, it's a darn good bit of work..and we're all doing it every day...just part of the gig I guess...FD isn't an easy thing...it gets to be a routine...so we all try to do our best 
). I've only posted when I've needed help, and it wasn't really coming, so it's been a bit frustrating. I think I'll start posting more just to be seen.
It has been stressful...but take heart, your Jazzy is looking quite good!