i think it was about 14 or so mins in that the first gateway opens the first section and then just don't kill the gateways until all the undiggable terrain is dug.
once you have the DBeam the top section is easy.
hope that helps
15 minutes to be exact! And then the gateway's next packet is 10,000 frames afterward which is BEFORE the next gateway, if you can make it down to the opening at the third ection at the bottom the 2 gateway will work at I believe 30 minutes if not just wait for the gateway up top!
Also glad you all liked the map! Working on the next one!