Are you trying to say you’re not a fan of needing to reinstall packages after an upgrade? It’s so simple with these easy to remember commands:
opkg update
cat /etc/backup/installed_packages.txt | grep overlay | sed s/\ *overlay// | xargs opkg install
The Linksys WRT3200ACM has A/B firmware support, but unfortunately that router is starting to get a little outdated. Saved me from a couple bad upgrades, but unfortunately it died on me about 4 months ago. I updated to the Banana Pi BPI-R3, which has been great for my network speed, but was a lot more complicated to set up.