Multi types and functions

I don't do it the same way you are but have you tried returning the instance of the type, ie replace return obj with
something like return obj\mesh?
Anyhow this is how I do it, but I don't know if it will be what you want. Hope it helps.

for I = 1 to whatever
cill(i)=Make_OBJ(1,False,False,12,cill(i))
next



;in function
Function Make_OBJ(shape,par,sol,segm,obj)

Make.RB_OBJ=New RB_OBJ
 
 Make\parent=par
 Make\solid=sol
 Make\segments=segm
Select shape  
 	Case 1 ;Pill
        ;Makes the main body and the two spheres for end caps
		Make\obj=CreateCylinder(Make\segments,Make\solid,Make\parent)
		Local spheresegments=Make\segments/2
		t=CreateSphere(spheresegments,Make\obj)
		b=CreateSphere(spheresegments,Make\obj)

		 body.objscale=Last objscale
			;Scale the pill and position caps
			ScaleMesh Make\obj,body\x#,body\y#,body\z#
			ScaleMesh t,body\x#,body\y#,body\z#
 			PositionEntity t,0,body\y#,0
			ScaleEntity b,body\x#,body\y#,body\z#
			PositionEntity b,0,-body\y#,0
		  

		
		Return Make\obj