Они в шахматах chess.com точно есть, поскольку есть достижение «Сумасшедший ученый — вы сыграли 10 партий в крейзихаус» и другие, которые основываются на шаблоне «вы сыграли … партий в крейзихаус» / They are definitely in chess.com chess, because there is an achievement "Crazy scientist - you played 10 games in the crazy house" and others, which are based on the template "you played ... games in crazy house"
Most of the variants are on the website. Other than 960, they are not natively supported on the apps..
For the achievements to coiunt, you have to be in the Play server and change Standard to the variant you want and play that way. Or Join one of the tournaments.