Tile backsplash - symmetry vs function
I am remodeling a master bedroom and would like to have a tiled backsplash for quartz countertop on my 48 inches vanity. I chose a very pretty marble mosaic and trim pieces with field tile underneath, but struggling how far to take backsplash length-wise. You can see from the picture attached that I will have some space on sides of vanity giving impression of a furniture piece. I feel my current 60 inches built in vanity makes space feel cramped, so I am willing to sacrifice some counter space. Now to my problem. Wall on the left side of the vanity is longer than one on the right (38 and 29 inches respectively). I was going to put a mosaic border and trim only on 60 inches wall, so I do not have to worry about finishing edges of a border and tiles. No way water will splash that far on the sides! But I got a very negative feedback from my friends, they think it will look unfinished somehow. Their suggestion is to take tile and border all way to the door frame on right and a corner on left. I would consider coming to 29 inches on both sides, so it looks symmetrical but it would leave a small part of wall untiled (9 inches) next to the corner.
I would appreciate if you shared your opinion about these 3 options:
1. Border and tile only on a long central wall.
2. Border and tile 29 inches on each side
3. Border and tile all way to the door on right and corner on left
Options 2 and 3 will open another can of worms - how to finish the edges of border and tile.
I guess there is always the last resort - a quartz backsplash... Which would be just on the long wall obviously, probably 49 inches long. Thanks!