The OpcodeList3 in this DNG contains a GainMap opcode which applies both vignetting and color shading correction. It also contains a WarpRectilinear opcode which in theory could correct distortion and CA, but in this file the tag values do nothing and it could have been left out.
The file is valid, but it won’t work with the GainMap implementation that I added to darktable 4.0 because that implementation only works with GainMap in OpcodeList2 (before demosaic) and this one is in OpcodeList3 (after demosaic). At some point I’d like to try to fix that, maybe by converting it to an OpcodeList2 GainMap that has almost the exact same effect.