The community seems to be divided onto explicit boundaries esentially being, as Rollo explained, a form of mate-guarding with negative long term effects and that a girl will naturally behave within reasonable, implied boundaries from a guy who is her "alpha", and on the other hand onto them being fine and even necessary if presented as "personal boundaries" and not just simply "controlling".

The first approach assumes granting total freedom and examining behaviour, and then nexting when implicit boundaries are breached, the second assumes stating them openly when needed/asked ("my girlfriend can't do..." etc).

Both have some sense to me. Any open boundary is preventing a girl from doing what she would otherwise do, which isn't ideal, and why does she want to do that which requires a boundary in the first place? However, it seems unlikely for any girl to perfectly fit in a presupposed mould of behaviour, especially over many years, especially in today's day n age.

What is the more correct approach?

Ok bro let me give you my take as an older guy with a different worldview. It sounds like you're looking for perfection in an imperfect world. You stated you wanted to raise your SMV. By all means, continue down that path. This is good for you. It's not going to change your results.

You're going to have to do some self reflection. For example I have usually attracted submissive women that are quite needy. It's because I took up a strong and competent role. I did it all myself because self reliance feels "safe" for me. Well in return I was not in relationships where I could get what I want. I was relying on myself and she was relying on me.

Do some digging and find out what about you is attracting these qualities you don't like. Putting on muscle will make you more muscular with the same problems. This isn't related to SMV.

Now, mentally unstable, or alcoholics are a very large red flag and are easier to spot. But some of this you have to put into perspective.

For example does a woman who believes in alchemy, really cause you harm? Does a woman who likes tarot deserve to be dumped because of it?

I had a girlfriend that believed in reiki. It didn't hurt me so it was just one of those things I would roll my eyes at when she wasn't looking. It's a small price of admission. Trust me when I say that you can be so picky that all relationships become short term and transactional. I've been there and it sucks.

Everyone has quirks and strange worldviews. These imperfections are what makes them unique and beautiful. If you find a girl that is straight laced and a perfect tradcon wife, you're going to be very bored very quick. Normal is boring.