After all, I am moving to Netlify, powered by blog.nuxt, which is also for SEO purposes.
Also, Netlify is easier for a more complex setup (uses build script), just like Heroku; but Netlify might load faster than Heroku for static pages.
Apparently, yesterday, I made a Chinese learning resources, aggregated from various textbooks. I plan to make it mostly in JSON format (see /resources）, for easy computerized parsing. I am a tech guy after all.