Travel and get H1B stamp using old H1B extension about to expire?

Thanks for your input

Here is the link where I saw that an attorney respond that you can travel 10 days before the start date

https://www.avvo.com/legal-answers/what-is-the-earliest-time-to-enter-us-with-a-h1b-v-98164.html

I have never heard of this before. Not sure if this really works.