wall bow.worktop &extractor - Tile Advice

[G1zm0]

Hi. Ive installed my kitchen and now onto the tiling.

I have a curved extractor. Can't get a tile in behind it when its against wall. So taken it off.

My options are. Tile to where coving starts. Tile to top of unit (but the chimney won't be flush against wall). Use 9 or 12mm ply to bring extractor out from wall then tile.

Its 7mm subway tiles. Was going to use a 6 or 8 mm adhesive bed . So should give me 4 or 3 mm layer.

Also my worktop is 3 meters and the wall bows in at middle for 6 inches along and 7mm from wall.

Should I skim this with plaster. Ad