I have been quite busy working over a powerful new major tool: Bridge
It can robustly connect any arbitrary part of meshes, being tunnels or bridges, with any shape and any amount of polygons unlike common bridge implementation in most modelers that requires equal amount of vertices per connecting boundary. Bridges can be accurately cut, smoothed and subdivided all at user control level. One powerful feature of this tool is that , unlike cutting holes with booleans, it can create holes with completely different endpoints shapes. And much more, the workflow possibilities of this tool are endless.
Hope you like it.