@AADuw 

I Understand now the requirements to reach this goal.

To wrap up this post How would 802.1Q (Isolation) be benificial in this case when setting up this home network ?

Thanks

  Simply having your devices in different vlans will help keep traffic "clean" where you want it clean.  This is especially true in regards for IOT devices and your CCTV network by both decreasing congestion on your main user vlan and giving you better control and visibility of traffic within all of them.  For instance, you can have a much more strict dns policy with Pihole or AdGuard in the IOT vlan, and that would cover a significant problem area since they like to collect data on you and your network.  Using ACLs to segregate it further wouldn't be the worst idea, but those devices likely don't have a decent way to even know about your other networks.  Some might be that sneaky somehow.  If you want to lock down your cctv network access to, say, just one host with ACLs, that would need doable too im sure.

You would have to assess your own benefits really.  If you want something anecdotal, I do not use ACLs to lock down a whole lot at home. Putting devices in appropriate broadcast domains will almost always be sufficient and blocking/blackholing things with DNS is even more effective. At least that's how I operate.