Here is no logic to give Pro WM users ability to de-select tiles for export, and continue calculate them while export
On this screenshot you can see that WM while Tiled Build did calculate all tiles, even un-selected, but just do not merge them to final image. With this logic i may just use Zero Constant device to cut half of the map by my own.
As user i did expect that un-selection of tiles will save my time, by not calculating them. I think this is should be fixed.
This is likely intentional so that any processes that happen in those deselected tiles that have effects that would cross into selected tiles (eg Erosion) are still calculated correctly. If they were skipped entirely, the calculation would treat them like normal extent boundaries, which may lead to unexpected or undesirable results.
In cases where you occasionally want to build only part of a map, using different Extents will likely be a better solution than deselecting tiles.
Editing to add:
This may also just be an unintentional side effect of the “Calculate edge tiles for partial tilesets” option that is selected. With 4 tiles as shown, all tiles are edge tiles, so WM is specifically being told to calculate them. Could be worth a try disabling that option.
Adding a second edit to add: I have confirmed on my end that disabling the “Calculate edge tiles for partial tilesets” option in the tiled build settings causes the tiled build to operate in the way you are describing.
Adding a second edit to add: I have confirmed on my end that disabling the “Calculate edge tiles for partial tilesets” option in the tiled build settings causes the tiled build to operate in the way you are describing.
Thank you for explanation 
, i’m feel bad that do not test it by my own
So now that ticket have no sence, should i close it/delete it or so? 
I’m always a fan of leaving threads like this up just in case someone in the future is having a similar issue.
