Hello! Based on my experience, it becomes a “not worth it” situation, primarily due to workflow. No, it’s not about a low strength. In fact, I find the EK43 to produce espresso at a higher strength. Always check alignment if you have this problem (low strength/ short shot times). The punchline is “it’ll be mixed with milk anyways so 20g,20g,20s” … from what I always encounter anyways…
The Mythos and Robur does not necessarily require a portafilter to grind coffee, meaning you could save a lot of time.
Respond to your market. If the people want to drink a lot of espresso + milk then design your workflow to optimise this. They love it when their coffee arrives early. If you are a low volume coffee shop, then use the EK43 even with espressos that get mixed with milk. Hope this helps.