Welcome @samesense ! It sounds to me like the manifest that you have generated is not set up properly to publish the website? Rmd websites can be a bit tricky to publish - you can get the proper manifest by downloading the "bundle" from your successful deployment. Or you can build a manifest with rsconnect::buildManifest()
Several of the different types of deployments have very big differences in what they mean for Connect behavior, so my suspicion is that the manifest you are using with rsconnect deploy manifest is different from the one you are getting when you use the IDE.
To confirm - rsconnect-python can deploy any type of content, provided that the manifest.json is generated properly 