Yes, but .....
I'm very doubtful if a traditional EA approach would work for a technology oriented startup if we look at their time line and how the market for where they want to sell their products evolves.
I did an Enterprise Architecture for a large start-up in Telecom, Media & Entertainment in year 2000 and it took 6 months for a pre-study. I don't see this working today as the world spins faster today than fifth-teen years ago.
My suggestion would be to use a framework like Technovision 2015 or other similar frameworks as guiding principles. Start with what is needed for a minimum viable product and supports the long term view. Very light-weight architecture combined with agile configuration. We could take a small assignment from PostNord as example, where we spent 14 working days to get up and running offering a new product.
IT is not the issue for a startup. It's about finding out what customers are willing to pay for. Building profitable services for consumers and business is a challenge, not manage IT-Systems.
... there is a much greater need for experienced Enterprise Architects than EA methods.
Links to other resources
1) Business reborn - http://disruptivearchitecture.info/blog/2015/9/04/business-reborn
2) Enterprise Architecture for startups - http://www.academia.edu/12840249/Enterprise_Architecture_for_Startups_A_Case_Study_of_an_Entrepreneurial_Small_Food_Company_in_Brazil
3) Need for speed - https://www.youtube.com/watch?v=UiqnAXvFpEM
4) Technovision 2015 - https://www.capgemini.com/blog/cto-blog/2014/11/welcome-to-technovision-2015
5) Leveraging Bluemix at PostNord - https://www.capgemini.com/resources/video/leveraging-bluemix-at-postnord