The player is mainly responsible for the sound….the mouthpiece is a relatively minor aspect.
Many can play high baffle pieces with a solid & thick top end.
I may be wrong, but I believe that Johnny Ferreira uses a high baffle piece.
Also Michael Brecker if any more proof is required.

i can understand the physics side of
what Theo is saying in his video.
In theory his design should fatten the
sound more than conventional mouthpieces.

I would have thought the combination of the
player & the setup has a major bearing on
a players sound? Surely if Johnny changed
his setup to a cheap shoddy made mouthpiece
wouldn’t his sound be impacted?

i can understand what you are saying.
When i listen to someone singing i can tell straight away – who the singer is because their voice is unique,
when it comes to listening to sax playing – i find it harder to say exactly who the player is, probably because
i haven’t spent enough time listening to different sax players!
But what i do notice is that regardless of the singer.
The type of microphone, room accoustics, sound engineers/equipment does change the recorded/played performance.
for example there is a minority of people that would argue that the beatles recording success was a lot down to their sound engineers?
I’m just saying that the type of equipment may give you an edge?
i’m not an expert, but it is interesting the different views people have, nothing in life is set in stone,
like Einstein noticed everything is measured relative to something else.

lol – 1st rule of public speaking – know your audience