My experience is much shorter than yours, but I was a software engineer for about 2 years before making the switch over to sales engineering.
I loved the switch, and I have many friends that did the same switch over the last few years. I loved working on fast-paced projects when I was in college, so being a sales engineering is a great fit for me since I'm constantly working with fact-paced projects with different groups.
Sales engineers are skilled at being technical and selling. My software background made it really easy for me to hone in on technical skills, so I mostly had to work on selling/presentation skills. The hardest skill for me to learn was how to demonstrate value; rather than explaining how a feature works, you want to explain why a feature matters.
I've met a lot of people in the role with SWE backgrounds; it's a very diverse role. I suggest checking out Mastering Technical Sales to get a better idea of what skills are required on top of your technical background.
Mastering Technical Sales is a GREAT book to check out; it'll map out the entire role and how you should think as a sales engineer.
Great Demo! is also a great book to learn how to create meaningful demos.
>!library genesis is your friend ;)!<
There are companies that also have programs that train you to be a sales engineer. Check out Salesforce's success graduate program for solution engineering
It really depends on your industry and what skills you already have. For me, it worked to be an expert in my field. Now, you need a loooot of soft skills here, you have to be an excellent listener, you need to know how to ask questions, how to develop relationships with others, etc. Check out "We the SEs" Podcasts and if you like to read, you have to read a loot if you want to be a really good SE, get and read this book, which is basically the bible for SEs. Hope that helps!