Careful. Tesla is using CCS signaling for A/C charging, and it switches to DCFC with the same 5% pilot signal. But once it switches it talks with CANBus signaling instead of the Homeplug greenphy that a CCS station would use.There are really only two standards: CCS and CHAdeMO. Tesla uses the same signaling protocol as CCS. Just a different plug. So it would be easy to have an adapter. CHAdeMO is a different story. It's a totally different beast. It's also proprietary.
And actually, there are four DCFC possibilities, because Tesla uses different plugs in the US and in Europe (3 phase power is more common over there, and EU rules may have required the Mennekes 2 port that they modified to take deeper plugs to handle the supercharger DC current.
In a lot of ways, the supercharger standard makes more sense from what I can tell - the common plug means it's always the same compact, simple outlet, the signaling is more flexible (full CANBus,) and the standard allows more power (at least 120 kW vs CHAdeMO's 50 kW and something similar for CCS I believe.)
But of course it's proprietary, and certainly having multiple standards is inconvenient and hurts growth for all EVs.