Very slow meshing when a whole surface comes from a 3D Scanner


I have a STEP file coming from a 3D scanner. It is composed of simples shells on the side but the upper surface is already 'meshed'. Meshing is taking a LOT of time (~10 min). I discovered that Debalella seems to detect that this upper surface does not need a re-meshing and could take the nodes as-is. Watson is unfortunately unable to do so and I need to use this one. Other more relaxed meshing params had a huge effect on performance with Watson (larger deflection meant faster meshing etc)

Is there a way to tell the watson algorithm to "not mesh face is smaller than X" ?

Thanks for yout help,