Unless your network is very simple and you are using the edge builds, i don't as yet recommend it.
OpenWrt's DHCP is far superior to AGH's and AGH team have not yet refactored their IPv4 and v6 mechanisms. It is due in 109 i think? (it was 108 but got bumped) (edit) it was indeed 108.
However setup your machine to have a static IP (because you will be disabling DHCP during this process) then follow the install script and when it asks you to go setup AGH via the webfrontend, you then disable openwrt's DHCP and set up AGH to be DHCP. AGH will take over as it will not detect OpenWrt's DHCP. You will need to re-setup any DHCP Statics you had in OpenWrt again.
Once you have confirmed you have AGH DHCP working then you can reset your machine to DHCP instead of a static ip.
You will also NOT need to add in the PTR to dnsmasq.
And if they ever complete this? Then we wont have to manually stop in the middle of the script.