An idea for technology sub-mod.

Technology wouldn't really make sense in lore as things have been relatively the same in terms of technology for thousands of years. The only times technology changed in Westeros were on the arrival of the First Men, then the arrival of the Andals, then there may have been some SLIGHT changes just after Aegon's Conquest - but technology itself doesn't really advance. After 8000 years, Westeros is basically the same - a feudal society ruled by lords and kings.

Westeros has changed significantly in terms of technology, the steady state of most of the political entities of Westeros disguises this fact. Westeros develops slightly slower than the real world did but it is developing, some examples:
Southern Westeros is clearly in an early modern period of historical development with renaissance levels of technology (minus the gunpowder) you have advance banking and a growing merchant class in the cities (who some nobles are beginning to marry as landholding becomes less lucrative- westerlings, arryns, corbrays), you have a renaissance rather than medieval level of armour manufacturing with elaborate plate and enamelled armour, yes the North has missed out on a lot of these developments but in the same way that the renaissance came late to Scotland and Scandinavia.

Dunk and Egg is in a more High medieval level of technology, the armour styles are more old fashioned with more great helms etc. The course of Fire and Blood vol 1 shows us the emergence of banking in Westeros, reforms to the tax system, sanitation in cities, theological reforms, and even the development of new seafaring techniques.

If we rewind back a few millennia the Andals are an Iron Age people fighting the First Men a Bronze Age level people, the Andals don’t ride in as medieval knights with troubadours and painting they are people on horse with stronger swords who later develop into a medieval society. Really the only people who have not developed technologically are the Thenn, if you put a Thenn next to a Northman or even better a Crownland merchant or a Reachman knight you can clearly see that Westeros has seen massive technological change since the Andal invasion.

Pretty interesting ideas. though i don't think Vanilla Tech system would fit, it'd be cool if there was a slow tech progress over Centuries of gameplay.