Thanks for the long response which I quickly skimmed.
To cut it short: We opted for this route, are very happy with the result, the feedback and the contributions. You may choose not to contribute or start your own project (as you already checked domains) but we are happy the way it is. The more overhead we generate (new structure, open source), the higher the possibility of failure and wasting money. Right now it’s a slim and streamlined project that has little to no costs of running which means we can leave it running for decades to come (if there is still demand). The manual labour is still there but as it’s a passion project, we want to invest that time but into the project and not into solving problems we don’t face. In the end we are an efficient operation and not a German Behörde. :)
Long term: Proceed with improving the database as we do everyday and see where it takes us with minimum overhead to guarantee longevity. So far so good. :)