rooting - Xiaomi Mi A1 - easy way to root and get OTA updates

I ordered Mi A1 which is the Android One offering in India at budget price point ( also in 36 countries going by the Wiki)

It is expected to get OTA updates for next two years , which means including Android P.

I would like to root it (looks to be straight forward) and

a) Install Xposed as long as it is on Nougat or if Xposed becomes available in Oreo

b) Continue getting monthly updates with minimal effort of unrooting or hiding root

My reading on XDA and internet shows possible approaches

1. 
   
   

   Systemless root with Flashfire app

   
   


2. 
   

   Systemless root with Magisk

   
   


3. 
   

   Hybrid of above with flashing stock ROM with MiFlash based tool

   
   

It's not clear to me and confusing to say the least as to which is the best approach and involves minimal effort and use of PC ( I have Windows XP 32 bit on which I understand MiFlash tool can run and Mint Linux for rooting )

Looking forward to a detailed reply , preferably based on user experience. The device should be with me in a week and I would like to implement the best approach earliest