mullion overlaps and adding mullions

Hi Again, Santiago -

Is it possible to tell window mullions to overlap at intersections so that there is not a small chunk left out when they don't repeat?

Also, I am having trouble seeing how to add additional mullions to a window or curtain unit, including the possibility of different mullion widths in same window. Is this possible?

Sketch attached to clarify.

Thanks,

Matthew Winkelstein