I did try video on OTC (so same as old ETC hardware) - it didn’t have enough processing power, and pygame was pretty inefficient at handling video, also the lower frame rate was a bit of an 'issue.
But it did ‘work’ … just wasn’t really useable. ( here is my post about it )
the ETSY is more powerful (based on CM3), so hopefully that will make it more viable.
and for sure, Id expect openframeworks to be more efficient.
of course, we have to have limit our ‘expectation’ here - the CM3 is not a desktop level processor, so there are limits, with something like video which is at 30-60fps, with a lot of data!
if you are interested in what levels of performance you might achieve you could run pygame / openframeworks on a rPI3b … see what you get.
as for why it’s not ‘advertised’?
I’d assume at initial launch EYESY first goal is to be an upgraded ETC, as this is very popular ‘as is’ , and I’m sure that in itself is quite a task for C&G (they are not a big company 
)
But C&G and the community have a reputation of taking things further after release!