So how is exporting and importing coming along cause unfortunately litematica is not a supported file format type for FAWE (Fast Async World Edit) So the exporting functionality appears to be there but does not function as well as importing. So is it future planning or left in by accident?

Are you talking about the 1.12.x or 1.13.2 version of the mod? The exporting was just recently implemented in the 1.12 version. (Before that, there were the export buttons, but they didn't do anything... bad habit of future planning in that sense, as it can confuse users... :/)

In the current 1.13.2 version, neither importing or exporting is functional. They are planned, but due to the flattening, the conversion is a bit tricky, and would need tons of extra code to support all special cases, and thus at least the importing won't be 100% accurate for blocks that depend on adjacent blocks for their state. I'm not sure atm if exporting to the old schematic format could actually work 100% correctly, or not at all, or also only partially.