Gnosis Mutlisig APP for other chains

just saw here: OpenZeppelin Upgrades: Step by Step Tutorial for Truffle

that you have an Openzeppelin app on gnosis. Do you have any plans to provide them also to the other EVM chains, like BSC?

Also is there a guide how to handle the Proxy function with the ABI/Without the dapp?

No plans currently to add more networks to the Gnosis Safe app.

Here is a tutorial to upgrade a contract through a multisig using OpenZeppelin Defender: