Sorry, I don't come 'round to the VS8F3 board often. Lets see if I can help...
If you've already installed the plug-ins to one (or more) of the VS8F-3 cards, then after they're installed, you can move the cards around and put them in any slot you want to. (You just have to make sure that you fill the slots up in order with effects cards - for example, if you have 4 cards, which you do, you can't remove the card in the A slot - the machine won't recognize the other 3 cards left in slots B, C, & D.)
If you still need to install and authorize plug-ins, then place the VS8F-3 card you're going to 'key' it with into slot A.
If you've formatted the hard drive and you want to re-install your plug-ins, then you have to do so with the proper VS8F-3 card in slot A that you originally authorized those plug-ins to (that particular card.)
Hope that makes sense and helps!
PS If you ever need anything right away, just pm me.