Bats haave prgress a hell of a lot in shapes, size and performance, but in one area i think we shoudl look to history and that is bat selection.
In days gone by when we were less fickle i cant see peopl eregularly coming out with bats too heavy for them etc.
These days we are making ego purchases ( we have all done them!) and going after big bats and trying to justify them because " it has a great pick up"
I think this is different to exploring your optimum weight where you do need experiementation to find what works form you, but in the past you tended to go from the lightest weighing bat, that you were pretty sertain you could use to simething neavier gradually.
Tip, hold a bat in your top hand and extend you arm fully. If you can hold that with out undue effort. i.e. no movement whatsoe ever for ten seconds then you bat is not too heavy for you.
You will be able under normal cirecumastances pklay all shots and have enough strength to play an innings.
All this optimum stroke speed etc will have limited effect if you do not have the FITNESS AND STRENGTH to use your bat.
Fatigue has a massive effect on skil. That is something they do not teach you in Pysics books i am afraid.
1) get the right weight of bat for you ( i agree an ounce or so shoyudl not have too much effect. 2 oz i think is a significent step up, but managable i.e a nicely weighted heavier bat compared to a badly weighted light bat)
2) get set up right. middle, pick up edges
3) DOnt change, unless given EXTREMELY good advise to the contry. Remember most of people have strong opinions on cricket. 80% are incorrect.
Only listen to proven experts if not in supply, then trust yourself.
4) I dont begrudge peopl espending money on things they like, or even love. Hell i have a room full of sports equipment, but i would guess that over 50% of peopl eon here use bats too heavy to encourage all round stroke play. It is only the last 40 years where professional were using more than 2lb 6 and they were still hitting sixes.