Zaid Alsalami, Shaykh Dr Zaid Alsalami is an Iraqi born scholar, raised in Australia. He obtained a BA from Al-Mustafa University, Qom, and an MA from the Islamic College in London. He also obtained a PhD from... Answered 5 months ago

Bismihi ta'ala

You will be able to find the view here. 

https://www.sistani.org/arabic/book/22/1728/

The emphasis is that the kafan be of one piece of cloth, and if needed to be sewn, then its own strings should be used. Furthermore, A.U. Seyid Sistani does not completely agree that it is makruh. Please see link.

And Allah knows best.