Three things:
Weird politics
Weird plant-things
Weird battles in which nobody dies

The world of the Viner Codex assumes the existence of a plant-based technology called vinery, beginning in the 1650s, though itself as an outcome of the Commonwealth of Britain created by the Agreement of the People.

In essence, think of something like present-day gene-splicing, but done with whatever technologies were available at the respective time. Which, in the 1650s, might well be more aligned with, say, Newton’s writings on alchemy and astrology, than with his better-known texts on mathematics and physics.

(Think of this also as centred as much on known ‘hard-science’ as we can make it. Not fantasy-fiction magic, though note that its roots are ultimately in technology more than science – more ‘how it can be worked’ than ‘how it works’.)

Think of this developing in parallel with the other mechanical, chemical and steam-based technologies (‘enginery‘) from each period. So by the 1670s, we might expect trees that act as static pumps, providing clean water – with all the impacts on health that that implies. By the 1700s, we might expect grown structures such as bridges – much as in north India in the present day. By the 1740s, we might see more active entities such as levers and cranes. By the 1780s, ‘plant-things’ that can begin to move – the equivalents of Cugnot’s steam-powered fardier of the same period. And by the mid-1800s and beyond? – well, look at the other technologies of the time, and extrapolate into whatever capabilities exist anywhere within the world of plants. It’s a lot…

There’s also an element of gender to this. If the Agreement of the People puts an end to arbitrary constraints on women’s roles in society, we might expect an immediate doubling of the scientific and technical workforce, just as those aspects of society are starting to take off. If we add into this the traditional professions for women, from at least the Middle Ages onward – such as miller, brewer and blacksmith, as well as gardener and farmer – then we might expect a plant-oriented technology to fit well with women’s expectations of the time. And if physical-technologies are seen as a ‘masculine’ domain, then grown technologies might well be seen as more ‘feminine’. This too provides a useful mirror to our own present-day world.

Another set of challenges would arise from the way in which vinery would be literally a living technology – a technology of living-things. In that sense, a technology based not on ‘control’, but on relating with that which is grown – in many ways, a relationship of equals, rather than the ‘master/slave’ relationships implied in so much of present-day physical-technologies.

So yes, the concept of vinery is somewhat of a ‘deus ex machina’ for the story – but it’s a useful way to help explore the social and political implications of all types of technologies in our present-day world. And especially so as the technology starts to develop a sentience of its own…