Value propositions are super-powerful for product managers, as they capture the market, the problem to be solved, how the product solves it, and why the solution is better than competitors. Unfortunately, although Aha has a value prop template, it doesn't include that last clause, the "Unlike competitors..." clause. As a PM, or anyone pitching the product, if you're not including that in your pitch, you're leaving money on the table.
It would be great if Aha added the "Unlike competitors..." clause to the value proposition template.
I think there's also an argument for having multiple value propositions for a product (e.g., if you sell it to different segments with different key competitors in each segment). But that's more advanced.
Under Strategy -> Vision. You can just change the title to what you would like. Just click on it in the table (below the diagram) and add the word "Unlike" if that works for you. Of course, you can also add other sections as needed and even pull them into the desired order. I am not sure this is a widespread use case that would lead us to change the default language used on that screen because it is so easy to customize.