Tony, never had any issues with warping, in fact he never had any issues at all. He only cut back on the number he did because of the heat/steam/ dust from the charcoal because of his health issues.
Robin Brown of AA Brown does very nice CCH without drama as does Tony White who is self taught.
CCH is like everything in life, not without risk. That perhaps is why Risk Assessments are topical nowadays where as forty years ago you just assessed the risks and got on with the job.