Mainnet and testnet runtimes

[metricaez]

Right now, the Polkadot SDK parachain template only includes one runtime by default, but there’s commonly a need for different setups for testnet and mainnet. It would be great if the template already came with a folder structure that separates the runtimes. Something like a common folder for shared logic and two runtime folders (e.g., mainnet and testnet).

My suggestion:

• Set up a default folder structure in the template, with common, mainnet, and testnet folders.

Reasoning:

• Makes it easier for developers to handle different setups for testnet and mainnet from the start.
• Saves time and avoids big refactors later. In my case I had to do it to configure a transactor for XCM. The same asset had two different IDs—one for mainnet and another for testnet—which forced me to refactor everything to split the runtime for the XCM config.
• Allows teams to define different business logic and perform runtime upgrades independently for testnet and mainnet, tailored to their specific use case.