I do not know if someone mentioned it before.

However, I would suggest, some changes for such project.

1) Why not to make this platform completely separate from ETH or any other DAPP system. Just make your own DAPPs system, POS based, with shareholders as nodes in it. And since Etherium was/is going to switch to POS, level of security should be the same.

2) For deposits you can use Bitcoin lightning network (in the future) or any other crypto-currency.

It will make the market:
1) independent from ether or other currency.
2) more income for shareholders.
3) more intensive for them to run a node - more security
4) faster speed of network.

Of course, it will only work if the project team would be independent from ETH team. Otherwise, it would be a conflict of interest as in case of The Dao and the recipe for disaster.