Official comment
Yes, we know!
Our plan is to completely remodel that V2 tool to work like our V3 ontraport pages platform.
Most users prefer to send typical text messages, because they tend to perform better, so we have not prioritized that project in favor of extending the functionality of pages and building Dynamic content and much, much more. But we are certainly aware that that particular editor is lagging, and we will get there, I promise!