Should I remove the nesting box?

[NavaTrace]

I have 2 bonded male zebra finches. They have a large flight cage and a variety of nests. A finch nest (which they ignore), a bowl nest, and a wooden nesting box. They love adding nesting material to the box and they sit in there during the day but only sleep in the bowl nest at night. In the last few weeks I've noticed that during the day, one of them is always in the nesting box. They switch throughout the day but one is always in there. I love seeing them hanging out together in their cage so I def noticed that only one was out at a time. My question is, do they think they are taking turns sitting on an imaginary egg? Is this bad? Should i remove the nesting box they worked so hard to prepare? Thanks.