Do we think there will be a Pro version of the Mk3i released? The outdated hardware (Elevate 4 sensor) of the Mk3i really bugs me.

Well, it's because the F8 went step up in the screen sizes in the two smaller models, but biggest didn't get any bigger screen. If you compare Descent to Epix which was more of the same timeline there's no such difference. 

1. I never noticed that before, and if anything it proves the current profile to be a poor accomodation, for example in teardowns garmin uses standard square batteries with empty space around them, I'm sure they could commission manufacture of round batteries to either reduce thickness or support increased screen within the watch face, on 51mm that's potentially 10mm extra diameter lost of potential screen, imagine that size for diving or tracking within same bezel size if not slightly smaller

Well I think it was pretty big talking point in the F8 release that the smaller ones got bigger screen and I at least was disappointed that 51mm didn't get any bigger. 

I'm not sure what does square batteries have to do with the screen size. Don't follow the logic where the size of the battery physically affecting screen size. Thickness yes, screen size, how? 

If the battery were designed to fit the watch shape, or if it was a square watchface you could put more battery in same space to power a bigger screen for same time or make it thinner for a hit on battery, instead of a humungous case just to power the same size screen for longer,

there's a limit on size before it's ott and 51mm is at that limit imo, i had mk2i for 2 years and hated the thickness though it was a great watch otherwise, link to teardown

www.edn.com/.../

Battery life isn't a factor in which size screen you can put. People are happier if the battery lasts longer, but there is no indication that the F8 two smaller sizes got any bigger battery with the bigger screen. 

Screen size is pretty much dependent on the size of the watch and the bezel.

Battery and screen tech then more affects the thickness. 

I didn't even notice, just look at the bezel size inside the 51mm fenix 8 and Descent and compare it to the 47mm fenix 8, its clear that's what they've done, its fine but the 51mm watches are thicker because the batteries are, no point increasing screen size only to end up with same battery life, its a commercial and practical solution to justifying the  price increase which you couldn't otherwise imo, given teric only lasts 24h its not necessary, there should be a 47mm descent imo

Yes, make bezels 1,27mm thinner and you have 0.1" (2,54mm) more space for the screen. 

Calculating the square inches for 1.4" and 1.5" displays the difference is little bit under 15% more. So putting 1.5" display would consume just about 15% more energy. I'm not sure that really would be so meaningful difference. I think I would take the 1.5" with 15% more battery usage compared to 1.4" display even if the battery size would stay same. Pretty same goes with 1.3" to 1.4", it's under 16%.

(Urf, I feel dirty calculating with these this freedom units).

I imagine apple watch offering a dive computer and fitness spooked them into making the 51mm trounce anything apple could produce, likewise mic/speaker which is a terrible idea calls via Bluetooth buds would have been enough, I'm happy with fenix 8 for now, if the pro comes with micro led and ai no need for descent for my needs

It's so cool about the 47 having the same large screen size. Will help underwater and great overall proportions.