You could put in a lot of work, just for read-only feature parity.
Or you could work some more, and have a competing product.
You seem adamant, that the former is a better path, but I don't quite see why would you do all that work for naught.
(Roam already broke my backup script 2 times, and there are better uses of my time than interfacing with a proprietary product, if there are better alternatives.)
You could say openness is “a feature, not a product”, and it’s a feature that could be retrofitted.