I'm torn on this subject because I believe there are benefits to both sides of the argument:
(1) LL becoming mainstream: More people will end up doing it, resulting in more qualified surgeons who train in this field, thousands more surgeries being performed (and thereby more research and development of better and safer surgical techniques with fewer risks), more manufacturers coming up with innovative and safer devices, lowering prices through market competition. All this to say, the fact that it becomes a more "normal" and safe thing to do will, to some extent, reduce the level to which people who opt to do it question their sanity.
(2) LL remaining covert: Height being one of those things you can't naturally change in adulthood, when people notice that someone suddenly looks slightly taller, not knowing that this procedure exists will not cause them question the possibility of surgery. Which results in them having no idea about this person's feeling of height insecurity (which is a really vulnerable position to be in, especially with people you see on a regular basis). *Most* other plastic surgeries (with some exceptions like nose jobs) can either be explained with excuses such as weight-loss, training, skincare (liposuction, face lifts, chin implants) or the fact that only a select few people actually have the relevance/proximity to find out (butt lifts, breast implants).
To many people, including myself, the fact that height is openly used as a factor to permanently judge someone deeply affects our feeling of self-worth, confidence and honestly, chances with women. People are just expected to be confident in their own skin, while being openly subjected to these judgements. When it becomes known that a person underwent CLL, I believe it reveals the extent of their insecurity and causes people to look at them in a different (and possibly worse) light.
So if I had to pick one, I would not want this procedure to go mainstream, but I would want enough people doing it under the radar that surgical/safety advances can still be made.