VNX1 mix of 1TB and 2TB with the same tier

Hi,

I have a VNX5500 with Mixed Pool setup.   Currently the pool is having 4+1 R5 (5 X 200GB SSD) and 4+1 R5 ( 10 X 1TB NL-SAS).

Customer recently purchase another 5 x 2TB NL-SAS due to budget constraint.

I was not able to configure as R6 so I was told to expand the existing tier with 4+1 2TB NL-SAS.   I would like whether this is allowed (I know this is not the best practice) or whether the 2TB NL-SAS space will be truncated.