I won’t deny the importance of having a coach but I also like the process of discovering it yourself. I look at all this as an experiment on myself and ofcourse I do that cautiously after being well informed (either by myself or via forums such as these).You ultimately did what I would've suggested. I went 28-32 and then, trying to save money, went to 40 instead of of 36. That was fine for swings and goblet squats, but too much for cleans, get ups, presses, double front squats, etc. I circled back around and get a second 28 and for a long time double 28s was my bread and butter before I then got a second 32. It took a lot of work to do get ups with the 40kg, starting with partials and slowly getting those partials a little less partial. Still working on pressing it, but I nailed pressing the 36 so its only a matter of time. I think if I had progressed to the 36kg and then the 40kg I wouldn't've gotten derailed and probably would've stuck to doing singles for a longer time.
Just my opinion from my experience with myself. I also think if I started working with a trainer who told me what to do I could've been more consistent and cut my time getting anywhere in half.
Regarding the bell size itself. I came to realise from my past experiences that I load up on weight too quickly. So this time I want to build the strong base before hitting the big bells. I am 38 now and only been doing KBs for the last year. And I have a goal of hitting 40kg KB presses for reps by the time I am 40. So I can always come back to heavier bell once I feel my baseline strength is solid.