There's no easy complete solution at this point. Mitigation with rugs will help cover up the choice you've made. My choice would be to sand, bleach and refinish the existing hardwood to match the color and sheen of the lvp. It would require really good color matching and stain/finish skills to pull that off. It is possible.

It’s normal and fine. Don’t sweat the small stuff.

A rug over the transition piece will just make it an awkward step. People won’t be expecting that little bump underneath. Just leave it alone.

Ok darn I guess I’m stuck with it.