It's a common misunderstanding that a professional license would be required to perform any kind of work which is not true of the professional engineering license.
Imagine some military institution or government body needs a piece of custom but trivial software. I doubt they will be able to hire contractor with unlicensed developers to do the job.
Sure they will - the body shop guys still do the build, the staff developer still does the design and the project manager herds the cats, but they'll add a licensed software engineer to review the design and the load bearing parts of the build.
You'd also see service providers start selling pre-PE stamped services - which is hardly different from the whole "go buy your SaaS from X who is (compliance regime) authorized" today. Just like today when you build a house, your general contractor goes and buys a pre-engineered truss and hires a bunch of laborers to put it up per spec.
