Different strokes for different folks.You're doing some of those things because it's your personal choice. I never expected that from my mom who has lived alone for close to 30 years (sans a few years across time she had a roommates) when I was back at home for breaks during my freshman and sophomore year or when I was home on weekends working during those years. Even when I was living at home for 9 months after I graduated college once my apartment lease was up in my college town. Nor did she treat it like that with me.
She certainly never had that sort of relationship with her roommates when she had them.
She didn't dictate a dinner time and expect me to let her know if I would be there or not. The default is we're both responsible for our own meals, my mom stopped making my meals years prior to that. Sometimes we were eating at the same time together, most times not.
There's room to let someone know you're home if it's quite late (I'm saying wee hours of the morn). Or nowadays with cell phones just send a quick message but a curfew? No. There's more about letting someone know you're safe than following an arbitrary time to be home which is less adult-like.
The OP is talking about an 18 yr old away majority of the time at college, I assumed your initial comment was pertaining to having an 18+ at home occasionally.

No matter where we are in the world and I mean that literally we know where other family members are; it’s how we function as a society in this culture. Most of us still eat together as a family. I’m glad you are comfortable with your relationship with your mother.
The basis of the relationship don’t change whether full or part time.