bubble.io is a great option albeit more technical than Webflow, imo. I haven’t delved into the platform so perhaps I missed it- but I am not sure if code exporting is supported and what the TOS of their code is i.e is it a locked system?
But either way, once you add user accounts into the equation Webflow becomes technical very quickly, and I am not a huge fan of building a core function around 3rd party membership platforms.