Oh. right. i get you.
I didn't realise the stabilization worked because of light conditions. Thanks.
As for the rest
Chin mount shows my bars and front wheel.
when leant forwards in the air chin mount shows the front wheel coming close better than a chesty. infact I think it makes everything you do in the air a little more dynamic.
a chest mount misses anything you do with your head, say a cheeky mech check lookback over a double or a cheezy one hander pointer at your mate stood at the side of the trail. I'd definitely prefer my POV to be pointing where I'm looking over where my chest is pointing.
I actually prefer that slight vibration from the Hero 7 to a gimbal too. a gimbal looks completely disconnected to me
Mc trail rider didn't poineer putting a go pro on his chin . MX riders have been doing it for years. it doesn't need to be lowered to show the bars or wheel either.
Copy n paste this into your browser
https://gopro.com/v/MJvZnQDE3edp0
(I had to stick it in a code link as the forum doesn't link the Gopro website's URL properly for some reason)
the POV footage is all from a chin mount with no lowered extension.
It's actually my first ever go at a biking vid (well...actually making any video) so don't be too harsh

But it shows the front wheel and the bars come in and out of shot just like they do when you're riding. Personally i think this is a more dynamic view than the bars always being in shot.
I don't think it's too bad considering it's shot by a complete Gopro noob in low light/overcast/light rain. you may disagree.
The camera you've linked still sounds like it might be better than a separate gimbal if that's what you prefer though