An enterprise (self hosted) offering is probably what my admittedly niche uses would require. Just kind of spit-balling some ideas really, to see where things are headed.
Any concept of separation of duties? Like Doppler level Owner / Admins who don't have access to the configs, they just create projects and give users access to edit the configs with them. Or audit ability, where someone can't see the secrets, just who made changes when?
How long is the history on each config? Is it permanent history? Or just some time frame?
Or how about universal configs? Occasionally I have something like an api url, a git repo, or an artifactory url. Which rarely change, but would like synced across all environments in a project. Or even across projects. I know I could cut and paste the value across environments, but mistakes can be made.