I guess I spoke too soon, on the 8th day of uptime my router finally went unresponsive and disconnected. Had to power cycle it to make it work again.
Still, this week was the longest I've gone without this problem since 3.3 launched.
I'm still not sure if it's a DHCP lease issue or maybe a memory leak that is slightly better in this beta build compared to previous builds and takes a while longer before softlocking.
Any setting changes I could do to try alleviate disconnections or extend uptime would be appreciated.