In decentralized applications, not just CHZ, test tokens play a crucial role in the development and optimization stages of new applications and platforms. These digital simulations of actual tokens operate within a testnet environment, allowing us to mimic real-world operations without the financial stakes involved in a live blockchain.

For the token gating application (first project), test tokens enable us to ensure that the gating mechanisms work accurately. This testing phase involves checking that only the token holders can access gated content, and the system can handle potential security threats or high traffic volumes. 

The NFT marketplace project (second) is a platform where users can trade digital assets represented as non-fungible tokens (NFTs). By utilizing test tokens in the CHZ blockchain's testnet, we can simulate trading scenarios, auction dynamics, and smart contract executions for the NFT marketplace. This process is essential to identify potential issues in trading, ensure the authenticity and uniqueness of assets, and verify that transactions are executed seamlessly.

In both cases, the use of test tokens and the testnet environment significantly reduces the risks associated with deploying untested applications on the mainnet. It allows for the discovery of technical issues and vulnerabilities while ensuring a secure, and optimal user experience once the applications go live.