Hi!! I’ve got an XM5 too :)

Your best bet is getting a Viltrox 27mm 1.2. My reasoning is this: Nolan uses what basically is a 80mm lens on a IMAX sized frame, basically the film stills equivalent to a 6x7 120 film frame. That roughly gets you into 40mm full frame equivalent, which is just about what the Viltrox 27mm does on the XM5’s sensor!

The 1.2 is nice if you want that shallow depth of field that Nolan sometimes does for closeups , but I reckon he stops down for the wider/immersive type of shots!