There is no panacea solution I know of today if you use the parental controls but I will share my fix.

The first router here is wide open and those I don't control connect there. The second LAN is the one with parental controls. Since my NAS is on the first LAN which I use, no issues.

As to expanding the WiFi I used another router as a WAP. Google "How to use a router as a WAP" if you don't know this.