When do you max prereqs?

[ShadowHM]

Also if you are going to spend points early as a PnB necro those points will be much more useful going into Bone Armor.

I disagree.

Points spent in Bone Wall always will give more benefit to Bone Armour than points in Bone Armour itself. If Bone Wall is part of your play style anyway, then you should be placing points there instead of Bone Armour for sure.

After that you should have Marrow Walks for the lvl 33 bone prison etc.

PLEASE do not advocate bug abuse here. If you are going to use Bone Prison, put points in Bone Prison.