The twisted holography program (1812.09257) describes a duality that is conjectured to be a topologically twisted version of the familiar AdS_5/CFT_4 correspondence. In the bulk this involves the topological B-model on \mathbb{C}^3. Including the D-branes on which the dual CFT lives, there is a backreaction that deforms the bulk geometry.
Recently, twisted holography has made contact with the celestial holography program (2201.02595) which led to the first concrete 4d/2d dual pair in asymptotically flat spacetime (2208.14233). I will try to discuss the role of branes and backreactions in this context and potentially some extensions that my supervisor David Skinner and me have worked out (to appear).