v3.3, starters, and MDX problems

[JohnTelford]

I can not get a gatsby-starter to support gatsby@^v3.2 and MDX. gatsby-starter-mdx-basic uses v2.32. Changing package.json to v^3.2 and running npm install, does build with warning the several gatsby plugins are not compatible with gatsby version 3.3.0.

Starter gatsby-starter-default uses gatsby@^3.2.1. Installing gatsby-plugin-mdx @mdx-js/mdx @mdx-js/react, and running gatsby develop has warnings src/pages/404.js, src/pages/index.js, and pages/page-2.js "warning Imported JSX component SEO must be in PascalCase." Changing SEO to Seo in the three files generates problem with several stack components.

Any way to get a site running with gatsby@^v3.2 and MDX?