Side tiles and narrow routes through the stack
The left or right edge matters because each tile needs at least one open side. Long rows and the Turtle's side extensions can therefore become bottlenecks ev
An open side is a route
The left or right edge matters because each tile needs at least one open side. Long rows and the Turtle's side extensions can therefore become bottlenecks even when their faces are easy to see.
Look for end tiles whose partners are already free elsewhere. Removing an end can release the next tile along the row. That new opening may be more valuable than a convenient pair in an already spacious area.
Do not ignore the top
Side access alone is not sufficient. A tile covered by another layer remains blocked. Read the side and top conditions together before deciding that a route is available.
Try alternating your scan between the centre and the outside edges. A move in one region may unlock a useful face in the other. The aim is to keep several options available, not to clear one corner at any cost. Explore the Turtle layout.