That being said, as long as it works, it works. And if your app is small enough never to get into the grey waters, all the better.
Are there any tools you recommend looking into, were I to take the next step? I don't plan on depending on CapRover to fill gaps in my knowledge for too long, but for now this product really is a good start for me.
Ironically it's best learned "on the job" (for me at least); just try to deploy your app from scratch. Play around with nginx/apache, letsencrypt, your db stack, packages installation etc. and get a working product.
I'm no expert by far in any of this, but think that knowing "just enough" about these tools really helped along the way. Up to the point where I can now use CapRover like tools with some degree of confidence, closing the full circle ;)