i put my trim flush to.
I think you are using genesis trim with the rubber strip but the strip is to rise the tile so it sits flush the tiles do not sit in the trim they sit flushcant uderstand what you mean as tile trim is desgined for the tile to sit into it, thus the trim will always be slightly proud of the tile. some tile trim as a rubber strip fitted to it depending on the thickness of tile which you can remove so the tile slips into the trim.
can you post a pic of how you fit tile trim please as im eager to learn new things.
I am with Sean fsy on this one personally. If trim sits slightly proud it looks cleaner as you can't see the joint