Sorry if I made it sound like untangle was an add-on.
It is a stand alone option that requires media (hard disk or SD card) to load it's interface and security options. It's not as robust as LEDE for module installs, but for home to medium biz, the interface and modules make setup simple and very effective with its logging. Has some o the best logging tools for a commercial router. Unfortunately it runs only on 1900AC/V2 and both 1900ACS versions only. No support for any other router. It's one not so well known option for our 1900 series routers, which is a hidden bonus, if you decide to try it out.
I am going to run David's build and see if i like it first. Just have to get use to wrt again... been so long and all. Packages are so varied now, and makes thinking of options a relearning experience. May go to Untangled if find issues, just to see if the Untangled crew has resolved them on their build.