How do you get "k" (captcha iFrame) parameter which is needed to solve captcha without loading the page with JS? I was under impression that this was not possible, without browser, for example Selenium.
And yes, I do know everything you said. In my testing I just came into conclusion that I need to have some headless browser to unlock and create accounts. I got Selenium working, it's just not inside my bots anymore. Not sure about RAM problem because my bots aren't 100% ready yet, but I won't be running Selenium browser (or browsers, depending how fast I need to unlock/create accounts) on the same server as where bots will be.
Edit. Nevermind, I just realised that the captcha datakey is constant, somehow I thought it changes between page loads, which means Selenium is not needed. I also tested how much RAM Selenium eats, and it seems to be only 4-5mb when running headless, but that doesn't really matter anymore.