[crystaln]

Regardless of what you say as a founder, if the growth is not there and a massive opportunity arises, your investors will push you to pursue it. You won't have much choice, and this is an empty promise you can't keep.

Personally I don't see why anyone would choose such a closed ecosystem in this era when so many great open source options exist, where we can read and edit source code, substitute components, and pivot technically in so many ways impossible with a black box unironically named Dark. There is just way too much risk around hitting the limitations of the platform or corporate shifts. Why bet your biggest investment on something you have no control over? That would be incredibly foolish.

If you want this project to be successful, open source it and maintain your competitive advantage by adding value not monopoly power. If you are actually concerned about lock-in as you say, don't lock customers in.