Sorry was out hiking when I had this thought so wanted to ask the question while I was thinking of it so only had my phone, and guess I wasn't very descriptive.
"extends Builder implements SimpleBuildStep"
So really this is a two part idea. When someone selects the "builder step" I've made in a freestyle build is it possible to force things to be checked, like the ansi check box. The other thought I was having is it possible to have it so when you select the builder in a freestyle job it automatically adds a parameter to the parameter section.
This builder step I'm building relies on a string input so wanted to make it as seamless as possible. As well as I said above I keep forgetting to turn on the ansi console in the freestyle jobs so I can only imaging the developers I'm making this for are going to forget too.