Qatar Airways seat map changes for particular A350 flight

Qatar Airways leased 4 A350-900 from LATAM Brasil, which came with different configuration of C30Y318 instead of C36Y247 (Qatar A350). Those plane will deploy on DOH-MAD route, then other European routes (Good news: won't deploy to Adelaide).

Presumably Qatar have to do this due to shortage of plane supply? (Qatar has more than 200+ plane on order now and would be delivered until 2022)

Summary: It's leased plane from LATAM Brasil if your seat map has changed.

QR is deploying the 4 leased LATAM 359's to Madrid (twice daily from May) as mentioned above, plus Munich (twice daily from April.) They've loaded inventory to sell the configuration of 30J and 309Y for the time being.  QR has tried to keep the planes on specific routes to allow same day outwards and return to DOH for flexibility and to manage the inventory differential to their own fleet, which you can't do if they appear randomly in the 350 network.  

I am booked in Y on the QR DOH-MAD return in July 2017. What difference/s would there be between the LATAM 359 metal and the QR 359 metal in Y?