AdS3 solutions in massive IIA, defect CFTs and T-duality

We establish a map between AdS₃×S² and AdS₇ solutions to massive IIA supergravity that allows one to interpret the former as holographic duals to D2-D4 defects inside 6d (1,0) CFTs. This relation singles out in a particular manner the AdS₃×S² solution constructed from AdS₃×S³×CY₂ through non-Abelian T-duality, with respect to a freely acting SU(2). We find explicit global completions to this solution and provide well-defined (0,4) 2d dual CFTs associated to them. These completions consist of linear quivers with colour groups coming from D2 and D6 branes and flavour groups coming from D8 and D4 branes. Finally, we discuss the relation with flows interpolating between AdS₃×S²×T⁴ geometries and AdS₇ solutions found in the literature.