It’s a big blingy look. Lovely. I would also like to see your beautiful ring with just the middle band to compare. Sometimes it’s nice to have different looks. Blingtastic and then a bit more understated. Different looks for different moods.
Try putting the thinner band at the bottom. It's like with hanging art, where you don't hang from small to big, but try to mix sizes (a bit complicated to explain, but mainly avoiding having "steps").
Yeah I would probably put a couple of 1mm plain spacers in there between the blingy bands lol. But im a huuuuuge spacer fan so take me with a grain of salt! I think your stack is lovely!