Nevertheless, I think it doesn’t hurt to know what to do exactly to promote good slurring technique and not solely rely on the method that should indirectly improve the slurs. I mean it’s in a way put up side down. Aren’t we doing slurs to improve our playing abilities?

I understand from Greg’s Largo stage material that slurs should only be thought as a result of changing SHAPE. That means we have our ‘Uhhh’ embouchure formation with already activated Aperture Corners and then we should do some work with the Aperture Corners to make the harmonic slur happen.

What I’m not quite sure of is what the action of Aperture Corners should be to result in most efficient slurring and still have enough potential to go high enough in the harmonic series without too much strain.
I see there are 3 possible ways to make the aperture opening smaller (isn’t that our goal here?):

1. Stretching the middle part of the lips outward from the center(No! Not smiling which is no longer considered a valid embouchure technique). I’m talking about stretching the inner middle part within the fixed embouchure.
2. Pursing – working from the mouth corners inward (and forward?).
3. Two above actions combined. That’s what I’ve actually seen being recommended elsewhere on the Brass playing resources and it was described as a commonly accepted method.

However – it’s easier said then done especially when you have to consciously engage a set of different muscles.
Maybe Greg could clarify this ambiguity.