Allow generic XCM execution

[Szegoo]

Following this post on the Polkadot forum: link

I would like to suggest allowing generic XCM execution on the Kusama system parachains. Kusama already supports this so I don't think it would be a crazy idea to allow it.

Some clear benefits of this would be:

• Possibility of transferring reserve assets on AssetHub into an account from a remote chain.
• Possibility to do two-hop reserve transfers.
• Doing native token transfers with XCM. This could make it easier for wallets and other UIs to do non-cross-chain transfers since they can rely on using the XCM standard for doing this.

[Polkadot-Forum]

This issue has been mentioned on Polkadot Forum. There might be relevant details there:

https://forum.polkadot.network/t/why-is-xcm-program-execution-filtered-out-on-most-chains/3765/5

[ggwpez]

There are still some things that need to be fixed. We cannot do this yet - same why it is also not advised to do so for any other production parachain.

[ggwpez]

But we can do something in the relays #1303

[acatangiu]

This is now allowed on all test chains (all chains in this repo), as well as on all Kusama chains: polkadot-fellows/runtimes#261. Polkadot chains will come a bit after Kusama as usual.

[acatangiu]

Polkadot system chains: polkadot-fellows/runtimes#345