You should use cloudfront, cloudflare or some similar service. They take care of caching your assets as well and I think are more trustworthy than some random caching plugin on wordpress.
Edit: I see you mentioning cloudfront on your blog post, what problems did you encounter when using it with wordpress?
Also, any reason for not using sanic, strapi or any of the headless CMS and building from scratch?
For Cloudfront, I eventually got it working. The difficult part was figuring out how to get Wordpress to serve the site when it received the request from Cloudfront. By default, it turned into a weird redirect loop.
I eventually solved it by futzing with all the options.
Re why I didn't use Strapi/the others? Once I switched to node / markdown, I told myself I'd fit in a real CMS, but never got that far researching it. However, I like the options you mentioned. Thanks for sharing!
Edit: I see you mentioning cloudfront on your blog post, what problems did you encounter when using it with wordpress?
Also, any reason for not using sanic, strapi or any of the headless CMS and building from scratch?