We propose a general strategy to build three-dimensional gauge theories with
four supercharges which enjoy a supersymmetry enhancement in the IR. The
resulting IR SCFTs admit topological twists with particularly nice properties,
as well as boundary rational chiral algebras such that the associated Modular
Tensor Categories are controlled by the topological twist. The theories arise
from a twisted circle compactification of four-dimensional theories of
Argyres-Douglas type. We develop a novel algorithm to compute or manipulate
protected quantities associated to these theories, such as ellipsoid partition
functions and superconformal indices and half-indices.