This is the first Asus release in 10 months for the RT-AC87U. For these past 10 months, my firmware was ahead of Asus's own in terms of security. So, why the sudden panic?
You can't jump back and forth each time one of us jumps ahead of the other in terms of fixes, you will go nuts reconfiguring your router from scratch each time you do so (you cannot go back to stock firmware without having to reconfigure everything). Just pick one, and stick to it.
In the case of the RT-AC87U, Asus has this device on a 1-2 yearly release cycle these days, which means my firmware will contain more security fixes almost each and every time, as I issue more frequent releases, based on a newer code base that Asus updates more frequently as well.