Yes !
Not sure which model or fw you are using, but I've been using it on rt-ac88, gt-ac5300 and rt-ax88 with newest stock and Merlins.
I stumbled over this "fair share" setup using limiters years ago, and I have never looked back after that. It's easy and works wonder, gets the most out of your line at the same time as it ensure everybody gets a fair share if needed. In my opinion, look no further...
1. Make sure hardware acceleration is off.
2. Let's say your routers lan ip is 192.168.1.1. Then type in 192.168.1.0/24 as the target, then your lines download and upload speed minus a little bit, and then voila...
Asus says you can choose between these three formats: 192.168.1.2-100 , 192.168.1.* or 192.168.1.0/24
I have experienced the last couple of years that I have to use one of the other format to get it working again after fw upgrades, but one of them works. I have just switched between 1.* and .0/24 notation.
You're maybe right that limit one client doesn't work, because I've not bothered trying it. The solution over handles everything… Best of luck
https://www.asus.com/support/FAQ/1013333