The vast majority of the time the reason your ideas are dismissed are because people don't see the value in them. Oftentimes, the easiest way to show the value

The vast majority of the time the reason your ideas are dismissed are because people don't see the value in them. Oftentimes, the easiest way to show the value is to build a vertical slice of that idea and show it to folks. In highly-regulated environments, this may not be an option, but for the vast majority of engineers, testing out different wordings, getting more seniority, or making allies will take a lot longer than producing a small prototype that can show the value. I think the analysis of why people don't like your idea should be saved for post-prototyping. The prototype should be a reasonable amount of effort, no 6 month projects ignoring the value you're being asked to produce, but more like a 1 or 2 day project when the workload is low. A good manager will encourage this sort of prototyping and not force you do it in secret. If you are having to build your prototypes in secret because people will prevent you from doing them, then you should be job hunting, because the place you're in doesn't trust you enough for you to thrive.