The Flint really is a nice bit of gear; it runs a little faster with the recent 4.3.2 firmware of 10 days ago too.
I’m sure you could do it but I doubt it’ll be through the GL GUI or be supported for such a custom configuration. The OpenWrt forums would be a far better place but before heading there it’d be advisable to have LuCI & SSH set up, ready to go… to make a backup before going deep into the config files: