I just installed an Archer A2300 and in configuring the parental controls noticed a couple items that really need improvement. My frame of reference for comparison is an older model Netgear I replaced.
The biggest obvious issue is that there is no default parental control value. You cannot apply restrictions unless a device is already connected. There should be a global default option for all devices, so any new devices conncting get a base level that can then be reduced if desired. For comparison, the Netgear does this, and allows you to then add filter overrides for specific users. Your method of assigning level by device in the web consol or app is much better in this regard, but there should still be a base filter option available.
The filter options are not granular enough. For "Teen" the default is "Adult Content" and "GambIing", which seems reasonable. However it appears for "Adult Content" you use the "Adult" categorization from Trent Micro, which contains these sub-categories: Adult/Mature Content, Pornography, S3x Education, Intimate Apparel/Swimsuit, Nudity, Alcohol/Tobacco, Illegal/Questionable, Tasteless, GambIing, Violence/Hate/Racism, Weapons, Abortion, Illegal Drugs, Marijuana.
Your Parental Controls splits out GambIing and S3x Education, but combines everything else, with no way that I can find of breaking it up beyond that, or whitelisting domains, so if you want to keep your kid from watching pornography, they also can't go to any site falling in any of those extremely broad categories. I have a choice of blocking everything in that list, or none of it, with nothing in between.
For comparison Netgear OpenDNS allows you to choose from about 60 different categories of web sites to filter. If you drill down into all the categories from TrendMicro they have a similar number, if not more. Being able to choose specific types of sites to filter, rather than the overly broad categories would be a great improvement. Maybe add that to the Parental Controls under the "Advanced" tab.
Consider creating a whitlist/bypass filter option for domains, so parents can allow a specific domain without allowing an entire category. For example, If I want to allow a specific music streaming site, but not streaming in general, there is no way to do that currently (or if there is, I can't find it).