Slices export

UDIM approach requires same sized  textures but  often we need just  slices from a big master image.     For example  I need to crop a thin narrow  32x2048 stripe  texture from 2kx2k master document.   An asphalt texture and  painted line  in the  center  .   Right now I had to export 2kx2k master material  and then cut manually 32x2048 painted line  from it .  Would be nice to do it directly in Painter