Adding drives to Storage Pool - does it matter how many?

Let's say I am building a Storage Pool with 50 drives initially in the "Performance" tier (RAID 5 4+1).  Does it matter if I add all 50 drives at once, or should I add (5) at a time?  I remember a long time ago I was told that whenever a pool is expanded, you were supposed to expand the pool with the same number of drives that you initially built the pool with, so it was recommended to add drives in the smallest increment possible (i.e. 5 drives at a time in this case).  This was probably 2+ years ago, so I am assuming this rule of thumb no longer applies?  In other words, with the current release of VNX OE Release 32/33, is it safe to add 50 drives to a pool, and then later expand it by 10 drives, and then later expand by 5 drives, and so on, without any negative performance impact?