Convert Mesh to surface in grasshopper

Hi im converting mesh from Maya to surface in grasshopper to use for Launchbox plugin but when converted it has to many surface that make my pc lagging how do i join the surface for minimizing surface

i try demsh face but its error so i am trying demesh and srf from point but I dont know how to find U count?? please help me

mesh to srf.3dm (4.0 MB)
mesh to (12.8 KB)

Not possible to make the mesh into a single surface.
To Brep, possible. Make the mesh into quad mesh, then subd, then brep.
If you want it light, try to retopology the mesh in Maya.