Bandwidth throttling / simulation for selected host
I make a VM when I need this and only install the conditioner on the VM. It’s usually no hassle for me to have the entire computer slow or lossy when I’m testing and then I return it to full performance when I’m done.
I suppose it depends on why you are wanting to have differential speeds out of the same network interface.  It’s really a lot of complexity to poke holes in the filter when it’s implemented on a per interface basis. I’m curious what your use case is for not just doing the testing and returning your network interface to full speed.