question about vxflex ready node

Hi, I am seunghwan koh in korea.
I don't know the expert of Vxflex ready node who answer my questions.
So I write some question, and please answer my question or let me know the email address which I should contact.

First, least number of drives.
Is it okay to use less 5 drives at one node of vxflex ready node?
When I make vxflex ready node with R740xd quotes and select less than 5 drives, OSC shows me the error message, "Scale IO Nodes with SSD SATA/SAS Hard Drives requires at least 5 of same type drives." and "2.5 SAS Hard Drives requires at least 5 of same type drives."
But, If I select SAS ,such as 1.2TB, OSC dosen't show that error.
Also, R640 doesn't show the error.
That is why I confused the minimum drives in vxflex ready node.

Second, R840 question.
BOSS card and additional NIC are in low profile?
As far as I know, Vxflex ready node with R840 will be released soon. R840 has 4 Full height slots and 2 Low profile slot. Therefore it looks like if 840 doesn't use a low profile BOSS card, then R840 must only have one GPU.
Also, depending on NIC's size, the maximum number of GPU, maximum number of NIC would be changed.

I see many spec sheets and brochure, but there are no answer.
Please let me know those things.

Thanks.