Down pipe.
On a relatively modern frame.
So, if it's built properly, to work well, the divergent cone and belly will be under the frame.
Unless they are limiting the travel - by means that make the units bottom earlier, it will have less chance of survival than a sun burnt snowflake.
Modern , long travel bikes leave about an inch / 2inches at the most between the frame rails and flat ground.
I like what they are doing, but, unless they are limiting the travel, or it's a flat track bike, it sure isn't remotely practical with a down pipe. So, building for a style they like = impractical bike.
Gives them precisely what they, I would assume, would not want from a bike. Impracticality 
When suspension travel started getting longer in the mid-to-late '70s they started running into this problem, and a fairly common solution (or rather, what Maico did) was to let the engine be a little higher in the frame, or even create a spot in the cases for the pipe to partially fit. This allowed the pipe to be partly between the frame rails rather than entirely below them. It'd still be hairy to deal with if it were done to the old standards, but considering they're putting an old engine in a new frame, I would presume they're doing a lot of inventive work anyway, so mounting the engine quite high indeed might not be out of the question. The main disadvantage with this route, and one of the major reasons down-pipes were phased out, is the tendency this has to raise the center of gravity of the bike. If I were determined to put a down-pipe in a modern frame (I wouldn't) that's how I'd do it.
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If they insist on a down pipe, it puts it into the category of a bike like a chopper.
I worked through the mid /late seventies (@ Competition Development - OZs version of FMF, and the importers of Fox Shox etc) during the whole LTR revolution, that's what much of my earlier fabrication experience came from. I know old school bikes, right through to the very latest.
So, put a down pipe on, then lift the engine - geeze that's going to really help the suspension with such a stuff up with the relationship between the countershaft, swingarm pivot and rear axle.
Maybe they intend to do a down pipe version of the YZ495 works Air Hammer Flat Pipe, that Carlquist etc. used?
Whichever way I look at it, it's a complete stuff up of what's Quite A Good Idea. Just make /modify an up pipe., Hunky and Co.
Here's an idea - they could do something like a Snail Pipe - that would be something different that would at least enable them to have a fully usable bike. And not just a styling exercise.
I love the simplicity of an AC 2t engine - I will regret selling my 490 for the rest of my life (though I'm currently pursuing one that I've found
) .
I'm even thinking of putting a AC 480 top end on a later model set of CR500 cases, in a new frame. That certainly appeals to me. So I'm far from being against hybrids, I've made a lot of them over the years. But they've been made to perform and work well. Not be slaves to a styling idea.
