As someone who’s set up and managed critical business applications I would say that it’s perfectly fine to host your own provided you have decent hardware that’s capable of doing what you need and as a dedicated business line to provide connection.
If you try to run mission critical business applications on a home internet connection you’re going to have a really bad fucking time. But hosting business critical applications on appropriate hardware and a 1Gb/s business connection with an SLA is going to meet 95-98%% of all business applications.
If something like that sounds expensive or too difficult to do then it’s too expensive or too difficult for you to host yourself. Just go with a provider and sidestep self-host.
It’s pretty great. The only thing you have to remember is that the caddy instance and the container you’re proxifying have to be within the same docker network. So you’ll definitely want to use the caddy2 container if this is the setup you want to pursue.
If not then you can just use IP addresses inside or outside of a container it doesn’t matter.