How exactly they were buffed?

It takes ages to grow a simple Hamlet! The feeling I have with the game is that it runs on Epic speed in reality. It is so easy to pillage Town/Village/Hamlet and it takes so long to grow one -- plus you have to work it non-stop.
In short, Cottages are the most complex and well thought improvement in BTS, I wish other improvements would have that "time-dependency", say Farms turning into barren land after many years of use, etc... All those cottages and humlets represent smaller cities, really. Real life Village is represented by that little house on the farm when you work that farm

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Look, city in this mod, given the scale of the map is representing Imperial city, town realistically represents provintial city, Village stands for the actual towns, hamlets and cottages are there to describe smaller urbanized population centers.
Real buff to Cottage improvement would be their ability to bring in income without being worked! That could represent what sprt wanted -- improvement acting like a little city! You cannot produce units there, but as long as there are cottages in your BFC -- city gets the benefit of that improvement without sending people to work there! One needs to work the mine to get the benefit of the mine, but how do you "work" town? People are already living there and they are working by themselves! So please lets think about that!
Speaking about buffed specialists -- why is that Tax Collector brings in Commerce? Canada Republicans would impeach you from this forums for that thought

No seriously, Tax collector should bring in Gold, while laborer and tradesmen do generate comerce by their hard work, as we have it now. I only wish with Engeneering Laborer could just get more productive, instead of inventing whole new Tradesman specialist. Less is more.