Open Brep problem

Hi guys! I've created a non planar surface, then i split it through 4 curves creating non planar subsurfaces. Now i have to recreate each split surface through 'edge surface component' (after using 'explode brep' component) in order to generate a local grid u,v.

Some of the reacreated surfaces are untrimmed surfaces created by 4 non planar edges and some are open breps created by 3 non planar edges and 1 planar curve. GH is able to generate the u,v grid only on the untrimmed surface.... why?!?!

GH gives to me 'Data conversion failed from Brep to Domain2' for error and 'Input parameter I failed to collect data' for warning.

How can i xform an open brep into an untrimmed surface?!?! or.... how can i xform a planar curve into a curve?!?!

Thanks to all!

Eugenio