there are a sort of huayan practicing called haiyin samadhi(海印三昧). but no one know actually what this indicates. and huayan itself contains the original concepts for both esoteric(dharma body buddha vairocana法身佛) and zen(dharma nature, pure mind 法性圓融, 一切唯心造) . so it's hard to say that huayan is only related to esoteric buddhism. i
in fact in korea, huayan sutra is totally realated to Zen practice. take a for a example, the ten grades of the bodhisattva(十地品) was reconciled with each grade of sammadhi in Ganhwaseon, the caracteristics of the seventh grade bodhisattva(七地菩薩) is maintaining pure sammadhi even in dreams, in traditional Ganhwaseon practice, there are a grade maintaining hwadu in the dream(夢中一如), then maintaing hwadu in the deep sleep-the eighth grade(八地菩薩)-.
unlike japanese rinzai zen or kwanum zen, traditional korean zen practitioners use only one hwadu to the bottom of sammadhi. so the interpretation of the grades of sammadhi would be different from other traditions, anyway, in Korean tradition, hwayan practice is totally zenized..
and tientai(tendai, chontae) school itself had no specific practition. there were a kind of practition called maha sammata-vipassana(摩訶止觀）. but there are no succesor now. futhermore tiantai school itself was highly hybrid in practice and theory. so it was very easy to be absorbed into other tradition or absorb other traditions into it. in the 16th century, Korean Chontae school was absorbed into Zen(Jogye), in China after the 8th century it gradually declined, and absorbed into pure land in Song dynasty. Only in Japan it absorbed esoteric practice. (so esoteric aspects in Japanese tendai school is very japanese phenomenon