Bug 1817834 will introduce a chrome only way to toggle JavaScript tracing.
But this is still tedious as it requires the following code to toggle it:

const {
  startTracing,
  stopTracing,
} = ChromeUtils.import("resource://devtools/server/tracer/tracer.jsm");
startTracing({ prefix: "myPrefix" });
[... run some code...]
stopTracing();

Exposing it on console via console.jsTrace() and console.jsTraceEnd() methods (or similar) sounds like an ideal location for such debugging API.
An incremental improvement would be to expose a ChromeOnly API easily available from all chrome globals and later expose it to all pages via bug 1827616.

For now, you could only toggle tracing from the debugger interface.
Having an API would help debugging tests and start'n stop tracing
from precise locations.
This would also ease passing parameters to have configurable traces.