I have never heard of CapRover and I dont know how to use it. I do know how to use Kubernetes across Digital Ocean, AWS, GCP and Azure. Just had to learn it once. I don't even use it for scaling. Not complex at all. I've used it for four years. Literally never had a problem with it. It just runs.
CapRover Droplet on Digital Ocean + deploy your Rails app with git. Scale your single VPS up as needed. Most don’t need much beyond that for quite a while.