Disable initscripts as part compiled firmware

I compile firmware for my Linksys EA6350v3 and WRT1900ACS and they have identical firmware except for the kernel as they're different chips. One router is my main router and the other is a dumb AP so some services such as dnsmasq and firewall aren't required for a dumb AP to function. With that in mind is there a way to disable them by default?

Have a look to the image builder, you can easily build your own images, and add or remove any package.