Use case 3.2 and 3.4 directly include constraints in radial velocities. It is a typical feature of some radio or interferometry cubes observing a single line to give measurements of fluxes for a given spatio-radvel coordinate or spatio-redshift coordinate.

Discussion in Nara initiated by Arnold and Igor showed that most people consider the RadVel axis to be different from the spectral axis. The argument being that we are facing two non permutable quantities as long as we are not considering a single , isolated spectral line.

Upcoming version 2 of characterisation DM will add a new RadVel or Doppler axis. It would be perfectly possible to add a couple of optional fields allowing to search against "radial Velocity" bounds and resolution...

This is the minimum required to fulfill the use cases 3.2 and 3.4.