you advance in stunning speed. When I combined 2 GRDM files I could only do that with MultiScene.
Your image looks like MultiScene where you stack ("blend") a list  of scenes. So here my questions:
Where did you get the 1SDV file from?
Can it also be read with reader 'sar-c_safe'?
There is now an S1B GRDM from yesterday December 13th. Didn't check GRDH, not enough memory.
Tomorrow 15th we should get an S1A GRDM/GRDH image that covers South Georgia and A68a again.