thingstodo -- Been a while. Remember the Toyota MGR days?
The Delta Pro Y-s two unit together to get 240V. Don't know about the waveform.
Here's another thing, secondhand low-cost solar panels:
1200 Watts for $250. How does the versatility compare with a home-brew solution? I think the fast charger is a big deal. Here's a review of the pre-Pro Delta by the same guy.
Ecoflow Delta Review: Pros and Cons/ Capacity Test/ Technical Discussion and More (Sponsored Video)
Beyond customer service, the problems seem to center on thermal throttling. There're uprated specs on the Pro.