I completely understand where you are coming from by not wanting to date shallow women.
I've seen one flame war in these forums because of a short woman who registered here and said she wouldn't date men under 5'9. While I think she lacked the awareness to understand where she was posting that, and lacked it further by not apologizing, remember it's also a two fold thing for them. We may personally feel short women should be the last ones to be so picky about height, and that they should be the ones who are the most comfortable with short men, but remember a lot of women aren't simply looking for flings, but possible long term partners. Think of everything very short men have to go through in life. It's very shxtty for them to vocalize their preferences, but they may be just wanting to avoid a fate like that for their sons (having very short sons, being short woman + short man). I'd say to still date short men and just do in-vitro fertilization if it becomes something serious, so you don't risk having sons, but this is not something that crosses the mind of most normal people.
Also, I'd recommend trying to meet other people in places where you share a hobby or a passion. Or look into older women who want to marry, not to date. General, unspecific online dating is probably not ideal for shorter men.
Second, leg lengthening is just that. Leg lengthening. Taller men are bigger. Larger frames, hands, feet, dcks (probably), torsos, etc. I would think a woman dating you would start noticing those things. It will start with little comments. "You have small hands". "You're only a size 7.5?" Stuff like that. Then what? I'm not saying this is an absolute or anything it just seems like leg lengthening wouldn't be a cure-all for being short.
This is mostly in your mind. Look at Trump with his hands. Henry Cavill with his short arms. Look at the amount of short users here with big feet. Torso length does depend on height, but most other things can be a stretch of your imagination. There are a lot of taller guys who look like twigs, with thin frames (despite the torso length), and you can see all these very wide, but shorter people, with wide clavicles, in places like Turkey.
I'm not saying this is an absolute or anything it just seems like leg lengthening wouldn't be a cure-all for being short.
It depends on what you want out of it. You need to examine that within yourself. I see the optimal use of LL, in regards to dating, as being something to get over the initial hurdle of persons you're interested in not even giving you a chance because of your height. But there are also a lot of other factors we can't control that make other people not give us a chance; height is just one of them. Either way, ideally, after LL, they'd stay for who you are, after having given you the chance and getting to know you enough. Most people can't even fathom someone used to be shorter in their adulthood. Looks are very biological in nature, and it's probably more about feeling than logic. Just imagine a tall woman who underwent limb shortening to get smaller than you are, in the opposite scenario. I think most people wouldn't give it much thought, as long as they feel attracted. It's obviously a problem, however, if you got someone interested in you mostly/only because of your height, and it could even ruin a marriage in the long term because they might feel they were cheated, if they learn about it much later.
I think LL is very extreme and I'm not trying to convince anyone to do it. It's a last resort, as people say. You break your legs, it's risky, and you spend a lot of time out of work; you need to be sure this will give you peace of mind and quality of life. I think you can find someone for you who won't care about your height if you keep looking and selling yourself well. We've all seen people in rougher conditions managing to find significant others. I'm just offering my thoughts.