Go with the cabinet maker’s plan. You will go nuts if you don’t have enough room to open the drawers and you will end up not using them, wasting important space in a small bathroom. If you go with a deeper tall cabinet, then you shouldn’t have drawers below, but maybe just open shelving, so that you can actually reach in and get what you want—towels, TP, etc.

Skip any looming tower. You need a minimum of 15” from the center of the toilet to a side obstruction, and the center of the lavatory drain to any side obstruction. You can do sliding doors under the counter, across from the toilet. That way they can actually conceal things, and have the needed operating room.

This is what you will end up with

Agree that cabinet makers design is better for small space. What are you planning on storing in the tower? The only reason I ask is 23” deep is not very practical for small bathroom items (lotions, soaps etc would get totally lost & even folded towels, linen are only about 12”) I would suggest you really map out what you want/need to store in there and then tape out or use boxes the dimensions of the design to see how tight it’s going to be. Build the shallowest tower that will provide the storage that you need. We have deep drawers under our sink and we love them, so for what it’s worth, I would trade the tall cabinet drawers for open shelves as suggested above, put drawers under sink instead of cabinets & do single door panel (not French doors) as shown in the cabinet makers drawing. If you have the ability to hang the vanity off the floor instead of a toe kick, that would help open the space visually, but not sure if that is an option for you.

I am with the cabinet maker camp. If I m reading correctly you have 35” in front of toilet. A 23” deep cabinet will leave 12” to stand and open drawers etc? Seems cramped. Also agree with Susan shallow cabinets can be great as they allow you to see & access contents easily, especially in the bath.
Also, btw your tile looks beautiful.

Thanks everyone. I just taped the floor and by the time I open the drawers (even if I'm opening them from the side and not in front of the tall cabinet), the drawers plus handle will hit the toilet. So I actually have no choice but to reduce the depth of the cabinet from 23" to 16". Unless I go with open shelves. I wonder why my designer was so adamant about never having a vanity sit proud of a tall cabinet. I really think I have no choice. I need the cabinet to be functional.