Let $X$ be a topological vector space or even a locally convex space such that its (vector space) topology is Lusin, i.e. there is some stronger Polish topology. Does there also exist a stronger Polish topology under which $X$ is a topological vector space or even locally convex?
Similarly, if $X$ is a Souslin vector space topology then it is known (p. 4) that there exists a stronger Souslin metrizable topology. Does there also exist a stronger Souslin metrizable vector space topology?