Hiya, there are a few parts to this query, so please bear with :) 

I have a Fritz!box 7530, supplied by 2degrees; lately I've been trying to understand more of its parental controls (through the Filter/Access Profiles settings within the router). I have set up devices that my kids use, onto their own Access Profile, to manage online time, but as discussed in my earlier thread, there are flaws with that - the online time progress bar does not show anything, so I can't monitor how much time has been used.  Devices on/standby and connected to the wifi will have their time run out, even if device isn't being used. 

I am thinking that the way forward is to either change how I use the Access Profiles, or look to a different router which has a user-friendly app that can quickly block or grant access to specific devices.

1) Access Profiles - currently they are set to restricted use. Should I perhaps instead by default block these access profiles, but changing back to Restricted when the kids want to use a device? And when they are finished (e.g. 1 hour into their 2-hour daily limit), block it again, so the time lapsed (while not in use) doesn't count? And unblock again later when they want to use more Internet. This still doesn't really solve the problem of tracking actual time lapsed.

Some devices are finicky to turn the wifi off/on easily (e.g. the VR), hence I've not done that way. I'm yet to give this (blocking devices) a try - I will later today. I'll also probably need to check out how to stop MAC addresses from changing / preventing new connections. I am a bit reluctant to do it (manage access) this way as the only way to fiddle with Access Profiles is via a browser. Their app has limited functionality from what I can see, and opens up the router interface in a browser if you try to dive in deep. 

2) New router - I see that a few years ago there was discussion here regarding parental control options and TP-Link Deco was what the OP eventually bought and was happy with. Would that router still be recommended today? I recently got a second-hand Nighthawk router to try out (as I'd seen another family member with that and the app looked pretty straightforward to use), unfortunately the Nighthawk didn't work so I've not been able to try that out myself (refund sorted). 

TL;DR version: Needing a simple, intuitive way to manage specific devices' access to the Internet (set times during the day, and a daily limit).

Thanks!