As a physicist who knows (something) about General Relativity, I'm accustomed to the term "maximally symmetric space" being an $n$-dimensional manifold with $\frac{n(n+1)}{2}$ Killing vectors. A demonstration of that can be found in Weinberg's book "Gravitation and Cosmology", but it is always assumed that the manifold is pseudo-Riemannian, and the connection is the Levi-Civita connection.

**Question(s)**: Is the above statement true for affine manifolds? Can you recommend me some bibliography on the subject?

*P.D.*: I'm interested in considering connections with torsion and non-metricity.