Unity CPU Profiler bottleneck identification changes across Editor and built-player profiling boundaries

When optimizing a Unity project, the CPU Profiler is the documented tool for locating frame-time bottlenecks, but the Editor and a built player do not produce identical measurements. I need to determine whether a hotspot found during Editor profiling is reliable enough to guide code changes, or whether a Development Build is required before acting on the data.

The uncertainty centers on two compatibility boundaries. First, Editor profiling includes script-domain reload and Editor-only overhead that can distort absolute frame times, while Deep Profile adds per-method instrumentation overhead that may create artificial main-thread bottlenecks. Second, the scripting backend changes the Profiler's view: Mono and IL2CPP builds can expose different stack traces, thread names, and marker visibility because IL2CPP may strip or rename methods. A bottleneck visible under one backend may not map cleanly to the other.

Because a Development Build offers accurate timings but longer build-and-run cycles, while the Editor offers fast iteration with potentially misleading overhead, the decision of where to measure remains unresolved. Does a CPU bottleneck observed in the Editor Profiler reliably predict the same bottleneck in a built player across both Mono and IL2CPP backends, or should profiling always be repeated in a Development Build before optimization? If Editor profiling is used for initial triage, which Profiler settings or workflow boundaries minimize the risk of optimizing a phantom hotspot?