Shameless plug: to run multiple of such security tools at once (nmap, openvas, nikto, etc) I've created https://gauntlet.io -- it's free for few days, but soon won't have such limit.
The idea is similar, but the implementation differs a lot: Gauntlt is a gem that will help you run multiple scanners, but won't extend scanner capabilities such as controlling the speed, add custom headers, etc. That's what Gauntlet does, including issue management on the interface for you to classify, notify people, build teams around applications and much more, without needing to know how to configure any of such tools. Gauntlt requires you to host it and Gauntlet is a SaaS. One of the reasons to be a SaaS is to reduce the complexity of running scanners. Of course, the name is almost the same, thanks for pointing out, although it have a reason. The name Gauntlet comes from physical punishment (https://en.wikipedia.org/wiki/Running_the_gauntlet) and it's like an app being 'punished' by multiple scanners. And as far as I know Gauntlt doesn't seem to be that active. And as I dug into it, I can tell: there are many things to do in order to make all scanners work together. It's more complex than it looks. But, anyway, thank you for pointing out.