بسم الله الرحمن الرحيم
(Fatwa: 447/357/B=03/1435)
This practice of your imam is not appropriate. There should be balance between both the sajdahs. It is better to read the tasbih in ruku and sajdah 3-3 times.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband
