Used to work for DellEMC on VxRail as a Solutions Architect. The reason behind 1 up 1 down is that it’s built primarily for “mom & pop” shops and SMB.

The assumption is that most places it will be deployed won’t have switches in MLAG or vPC, and to cater to the widest market they went for this NIC teaming. The team behind this also don’t have the strongest networking background.

We were told that it can be edited afterwards if the customer really wants LAG, but obviously the customer does this at their own risk. I’d recommend to raise a support case and state you want LAG and at least they can get this added to your notes.

If it’s on the vSAN NICs too (do you have dedicated vSAN pNICs?) this should be isolated from your ESXi management and prod traffic, so at least this is safe from any LAG related support issues.