Asustor Lockerstor 10 AS6510T write speeds + raid rebuild time

[Harridly]

Hello

I am thinking of buying the Asustor Lockerstor 10 AS6510T but I am concerned about the write speeds I will be installing a 32GB ram module and two nvme 2TB so with that in mind with a raid 6 over 6 hard drives what sort of write speeds will I achieve I would prefer to buy the Pro AS7110T but it is way over priced for what it is so the AS6510T is the nas of choice as that £1100 saved can buy a lot of hard drives.

Also what about expanding the raid array how long will it take say if I popped in another two 18Tib hard drievs how long would it take to rebuild the array

Looking forward to your reply, and can anyone report about the overehating hard drive problem that i have been reading about on thsi forum if all hard drive bays are occupied.

Thank you