I don't know if this will help at all, it's just my experience in trying to reconcile my poly relationships.
Although my bf had lived rather close by, it was always hard to leave him or leave my husband, always leaving one of them. There was that *pang* of regret that I always seemed to be saying goodbye to one of them. I saw my husband every day but it was also hard not being able to see my bf everyday, even for that mundane *kiss goodbye* when he left for work, or a *quick hug* before heading out.
I had the desire very early on to have my bf live in the empty basement suite downstairs. There were many practical reasons, but also there was this strong feeling that it was right, that he deserved a place in my life, my family. When he did move in, all of that was confirmed. It wasn't stressful, in fact it was very calming. A routine and balance has been established that is made much easier by the close proximity.
Before we got to that point, there were discussions about possible concerns. The main concern from my husband was that the home that he and I shared would be respected. Our bedroom, our space was still to remain ours. He wanted to ensure that my bf wasn't going to have free reign over our home, boundaries would still be respected. My bf also had a similar concern, that I wasn't going to come and go as I pleased. He also wanted to ensure he had space to call his own. Basically, all doors in the house would have the option to be open or closed based on the knowledge and comfort of everyone. I still knock before entering, everyone does.
Of course there was a bit of NRE in the beginning having my bf right downstairs, however I'm not sure if I would say we spend more time together now. There's just a better balance of time, less time spent traveling, easier scheduling, etc.
And most important, that *pang* of having to say goodbye is gone. Because I'm not going far, just up or down the stairs. Knowing how close each of them is to me, it's made me incredibly happy. I think it's also comforting to each of them to know that I'm close by, that I'm still 'at home'.