Again, this is even more complex than you are aware, particularly down the line.
However, generally, one 1041 is filed and it combines the trust with the estate; the estate box is checked and the trust is treated as part of the estate in most cases. There are some distinct advantages to doing so.
See (for example) https://www.thetaxadviser.com/issues/2013/dec/clinic-story-02.html
(note that separate accounting needs to be maintained)
Regardless, the estate receives the $600 exemption.
