I suggest add the contour on the top when use "tri1&quo

It is possible in the next version root?

Yes we can try to add a new option a bit like SURF3 but for TRI option

The top contour has many choices :cint ,cint1,cint2,cint3,cint4
Best wishes to you!

Did the new root add the function?

No, not yet. No time to do it.

Do you really want to have the same plot as the SURF3 option does ?
If yes, I am afraid that is not possible to do because we have no way to draw the triangles with hidden line removal. We can get something close but that will not be the same. Have you an example of picture you would like to get ?