Martineau
Part of the Furniture
The OP had success with my VLANSwitch.sh script to use with a downstream Cisco 2960XAhh ok. I remember using tomato and ddwrt over 10 years ago and must be where I saw vlan type options. I'm rather partial to merlin, so I'll take a look and see if i have other options.
Help setting up VLAN on ASUS RT-AC68U
I can PM you the script if you want to try it.