Many premium applications (like QLab) have reasonably priced rental licenses (daily, weekly) or free tiers for basic use. The small upfront cost is a tiny price to pay for stability, safety, and professional support.
There is a third, highly technical meaning of "crack": a security exploit. For example, the file cue.sh is a known exploit script that took advantage of a local root vulnerability in old HP-UX operating systems. More recently, a buffer overflow exploit was discovered in Numark Cue software (version 5.0), which could be triggered by a specially crafted .M3U playlist file. For a modern user, this highlights that using legacy or unpatched software can expose your performance system to cyber threats. show cue system crack