Kazakh mix alot of their native tradition in their Adat (عادات‎‎ ) with Islam before they were annexed into the Russian empire. Many non-Arab Muslims, especially those peoples who were never part of a Muslim Empire have their own Adat with rules contrary to Islam. The Kazakhs were nomads when they converted and outside of the sedentary empires of Transoxania.
The Chechens were never conquered by the Ottomans, when they were converted they kept their own customs like forbidding cousin marriage up to the seventh generation. So if someone asked them it cousin marriage was allowed and compared it with Arabs, they would see a big difference in opinion.
The Minangkabau in Indonesia have their own adat. Their society is matrilineal and inheritance is passed on through the mother.
The Sultan of Yogyakarta in Indonesia appoints spirit guardians to perform rituals to keep the volcano spirits happy, and I'm pretty sure that isn't supposed to be part of Islam. Some Javanese also believe in the Goddess Nyai Roro Kidul.
Merapi volcano's 'spirit keeper' walks line between tradition and technology | World news | theguardian.com
Malays and Indonesians have their own Adat, Chechens have their Adat, Central asians have another Adat and they will contradict each other.
I have noticed that Turkic peoples are very casual when it comes to Islam. This is has nothing to do with the atheist Soviet union as Turkey is also mainly secular and we never belonged to the Soviet Union. Uzbeks and Uyghurs are the only exception as they seem to be culturally very Islamized. I thought that Indonesians were mostly secular Muslims but I couldn't see anything from it in that study. Most Indonesians seem to be conservative Muslims.