I am or a doctor and have no medical training. I can only tell you my experience. Though I was not overweight at the time, my original diagnosis (which may still be true?) was Type 2 - between my age and relatively manageable BG.
Though a c-peptide test was inconsistent with this, I tested negative for GAD65 antibodies, so that diagnosis stuck. Initially, I tried orals, but after a lot of problems went to insulin 4 months after diagnosis.
As it was, I needed to use rapidly increasing amounts of insulin. I had frequent spikes - not over 400, but into the high 200's. Basal amounts of 10U quickly rose to 56U and my I:C ratio varied between 1:5 and 1:3. I also gained a fair bit of weight, which did not seem to coincide with increases in insulin needs. I was careful to follow a "Good diet" at a reasonable level (1500-1800 calories) and a moderate amount of carbs (100-150g). I exercised almost daily. Meanwhile. my c-peptide, which reflects the amount of insulin I am producing, came back lower and lower each time I was tested.
Not - I am NOT advocating any particular approach to eating, care, etc. Last year, I decided that I was not happy with the way things were going, so I made some bigger changes in my diet. I reduced my carb intake to around 70g/day and tried to incorporate some "healthier" foods into my diet. I still ate more or less what I wanted on weekends. I lost a little weight that way, but ther ewere few other changes.
Last June I made some bigger changes. For three weeks, I avoided grains, dairy, starchy foods and higher carb fruits. I also stopped using artificial sweeteners (though I am STILL not sure that matters!). I ate a lot of vegetables, berries, fish, chicken, etc. during that time. After that, I added some of those foods back, slowly, but I kept my carb intake below 50g/day (though I still "cheated" on weekends). I tried lower carb, but had a lot of energy problems, so increased a bit. IN addition, I tried to get some exercise in every day. I lost a little more weight, but the biggest change I saw was an almost immediate need to cut my basal dose in HALF. The lower-carb eating did not seem to change my I:C ratios much, but I was obviously taking a LOT less bolus insulin.
I was never a "fan" of a very low-carb diet, but I'm starting to change my mind a bit... I have a long way to go to where I want in many ways, but this approach has seemed to help push me on the way.
By the way, my last c-peptide came back low enough that my endo declared me Type 1. Don't be discouraged if your case "progresses" at a rate that is different than someone else's. Everyone, as you said, is different. And "Type 1" as an adult" does not always present in a slow-progressing form as is "typical" of LADA. Many people progress rapidly to needing insulin - and a lot of it . That does not mean that the progression will continue unabated. You will reach your level of needs and, unless other conditions exist, probably level off for some time. Keep a head up and do the best you can. My endo tells me that there is no "good or bad" amount of insulin to use -- you use what you NEED, and that is unique to YOU.
Oh -- and welcome to TuD!