Compatability of Firewalla Blue with either DD-WRT, OpenWrt, or pfSense

Hi everyone,

I've got an older Firewalla Blue that I currently have running on my network, love and enjoy it immensely. I'm looking to take an older WNDR3700v1 and set it up with either DD-WRT, OpenWrt or pfSense (I've always wanted to try this), and I was curious as to the best compatibility with my Firewalla Blue and those options. Does anyone have any advice or suggestions?