Bitdefender has become highly resilient to these methods. Most modern versions leave hidden files or encrypted tokens that are not removed by simple registry cleaners.
How Bitdefender trial works (concise)
If a paid subscription incorrectly shows as a "trial" (common after a device factory reset), you should remove the device from your Bitdefender Central account and then re-sign in on the device to sync the correct license status. bitdefender trial reset
A tool to mask or change your hardware ID (MAC address or HWID). Bitdefender has become highly resilient to these methods