I know you've ruled out the mono NF, but have you considered the epi version? More structured and not too flashy.
Dior panarea is a nice option too. Classic cannage quilting, lightweight, structured and roomy.
The Chanel GST is a (more expensive) option, which is also structured and more formal.
I also like the Celine belt and trapeze bags. Celine also have the more utilitarian cabas tote, which is functional and made of very luxe leather, but very plain and not very structured.
Tbh, for me, I use totes to "tote" stuff around i.e when I need to carry a ton of stuff, so weight is a big factor for me. That's why I will probably always go for a canvas/lightweight tote like the canvas nf, goyard st louis, or dior panarea. I don't know if that's a factor for you, but I think you should consider the weight of the bag itself, as these leather totes are always heavier (when empty) than their canvas counterparts.