Well, there are some superstitions all over the place. Sometimes is good to satisfy the superstitions in order to keep it up. I'm so superstitious in this sense, that I even buy new exact match TLD to try to achieve an optimal match

(for example: dallas.attorney for "dallas attorney keyword").
But regardless of that, in this case, if you eliminate the rewriting after being done as Study Force has done, it will literally kill your site in terms of SEO.
You might need thousands of manual 301 to redirect the old P-URLs to new non-P-URLs. All the internal linking done through P-URL will be destroyed, and all the external linking should be audited in order to create the new redirections also (at least the most important backlinks)
Anyway, here are all the reasons why statics URLs are a must for all marketers
https://moz.com/blog/dynamic-urls-vs-static-urls-the-best-practice-for-seo-is-still-clearAlso, I have a "theory", when you link build with a P-URL you are actually inputting an anchor text in the link. For example. If your anchor text is "Dallas attorney affordable" and you have a link like dallas.attorney/affordable you are creating a direct link but indirectly contextualizing this link. This means that both the link and each part has the wording for semantic SEO purposes (as href=...> + the URL itself as the anchor text. So in this sense, you are doubling your linking "power" by the link itself + context.
But as I said, in the beginning, may this be just a superstition.