Sadly, they will probably do this badly.
First, they will exempt businesses with less than “X” dollars of sales. That will take care of a lot of the business.
If they were smart, they would then put into the law a requirement that states have to sign up to be part of this new program, and that in order to sign up, the state has to provide an online resource that will provide current tax rates by zip code.
Or the law can require that the state set a single rate for this type of collection, and the money is remitted to the state, who can then figure out how to send parts of it to jurisdictions within the state.
It’s not like we live in the horse-and-buggy days. If you are doing internet sales, you have a computer and internet access, so it should be trivial for a state to set up a web-based server that will provide tax rates by zip code.
This forum is beginning to look like DU every day.