Here's the screenshot that Matthias sent of what the default VE toolbar looks like on Flow.
I assume that we could hide the components that aren't useful for us, but even then, I think it feels really heavy above the entry field. It's a lot of controls for a small entry field.
So -- seeing this confirms for me that we need to use Pau's design (also attached), which puts the controls inside the entry field. If that turns out to be unexpectedly crazy harder than we expect, then this would be a distant second choice for v1, but it would have to be a pretty extreme version of harder.