It's Awesome. Such an Innovative idea. I am wondering how it will work in real-time if the servers are different? IDK, if it's possible
But Look like both Project has The Same Owner. Maybe?
Yes duckdice and tower.bet are under the same management/team/owner as per below reference:
Welcome to Tower.bet - new platform, launched by DuckDice team!
That's why they can implement the new feature "voucher" to deposit and withdraw from one to another.
Probably it will be a trend and some other sites will be motivated to have the same feature especially for those gambling sites that are under the same owner like P and S.