No problem! And thanks for the kind words!
My concerns with this request are both philosophical and practical:
1. Philosophical: It really isn't withing the purview of a "Parameter Separator" plugin to start modifying other elements of the Jenkins UI. I think it would be weird, and would be annoying to remember to maintain.
a. The "Build" button appears to be pretty hard-coded; even if customizable, could potentially lead to an internationalization nightmare.
b. There is already a major push to refresh the Jenkins UI in general, and this feature request might be better suggested to those folks.
That said, I agree with the desire. Where I work we also have deploy jobs, and it would be nice to have it contextualized. It's likely be "cleaner" if there were a dedicated job type perhaps, although that would be a lot of overhead to just change the label text on a button!
I will look into seeing if I can do something, either with this plugin, or another plugin.