Mai needs to fuck around and find out with these changes to her appearance that she's considering. The strongest indication that she fucked up is when there's fewer subs and purchases of her PPVs start to decline over a period of weeks or months. As much as capitalism may be flawed, it's good to let a person know their poor choices are affecting their customers' willingness to buy into their content - with everyone's limit being somewhat consistent even if it varies (i.e. would the lip filler have been one person's dealbreaker and another person's might be implants if she decided upon them?).
Obviously this is very indicative of my own tastes, but LailaASMR is perhaps the most attractive one out there and very natural. But the lewd stuff she has made is low quality and I wouldn't keep my hopes up for anything new. LunaRexx is absolutely stunning and has a natural body. She is rather heavy on the make-up so is Maimy at times. Her production quality and level of lewdness is similar but with Luna it always feels mechanical and not quite as intimate.
The biggest thing I disagree with you about is HeatheredEffect, she hasn't just had "some" work done, she has had a shitload of work done. At this point she doesn't even look like a human to me. She's like if a horny alien was asked to describe humans from memory. Thankfully Maimy is a long way from that and lets hope that she doesn't ever go that far.
This is a funny way to see how people's tastes differ from one another. Honestly out of all of those asmrists you mentioned the only person I would consider comparable in attractiveness (and natural charm) to maimy is Jelzy. I would also add princesshaze to that, though she does full porn and less asmr now so is not as comparable to the others. Maybe I would also add Jinx in there as comparable in terms of looks, though her asmr is definitely not nsfw.