As for the "cheat client" you're referring to, I assume you're talking about a third-party software that claims to provide unfair advantages or cheats for DDNet. I must emphasize that using cheats or hacks in online games is generally against the terms of service and can lead to consequences such as account bans or penalties.
For the curious but cautious, here is exactly how downloading a DDNet cheat client typically plays out: ddnet cheat client
Running an online game for several years has revealed that DDNet often attracts DDoS attacks , leading to hoster bans when protections are insufficient. As for the "cheat client" you're referring to,
For those looking to host their own environments, the DDNet Server Configuration Guide provides details on how to manage your own server settings and potentially test custom client interactions in a controlled setting. For those looking to host their own environments,
— A DDNet player
if a specific feature is considered cheating on official servers? Downloads - DDraceNetwork
Many games rely on community reporting to identify cheaters. Players are encouraged to report suspicious activity, which can lead to investigations and bans.