You might think that testing wireframes makes no sense and it's a waste of time. Let's imagine the opposite — suppose you wait until the final product is ready. The product is launched and users are already exploring it. User feedback shows UI inconsistencies, unappealing design, navigational issues, and other bugs. At this point, it'll cost you a lot of time and effort to investigate problems and find solutions.

So that's the main argument for wireframe testing — it's simply cheaper. To test an iteration you only need some hand-drawn wireframes. Get feedback from users, colleagues, and stakeholders to validate your ideas. Each new iteration will provide incremental changes making your designs better and better.