This is applies to the boosts, Gen and Lt are NOT boosts.
Duplicate boosts only pay the extra 5 discards if they lose, winning duplicates do not pay extra.
Extra Upgrades (+2)
Extra Salvage (+2)
Reduced Discard (-2) - This applies to the "Discard from the Vault"("Discards from Deck" during Round 1) as per the table in section 4.2.
Tinkerer - pendulums of one target Element now count as your own Element for deckbuilding percentage and upgrade rules. You must use your own team's mark.
Sideboard of 3 cards - the first game must be played with the full deck. Before each match, you must import the deck from vault tool. After the first game, you may remove (up to) 3 cards after importing. If any of the three cards are upgraded, you may reallocate these upgrades elsewhere in the deck. The deck played should always be at least 50% in-Element, and should always contain at least 4 in-Element upgrades.
Mercenary - Can use 4 or fewer Elements in the deck; deck only has to be 40% in-Element.
Gambler - bet the scoreline on this deck. If the scoreline is right, you win 4 relics.
I think the idea is that you can stack the same boost multiple times (like multiple +upgrade, salvager, or gambler) but in the case of ones like mercenary or tinkerer, there's no point. There is also obviously no point in stacking reduced discard. I'm not sure whether multiple sideboard would let you play with a bigger sideboard or not, or whether that would even be practical.
For some decks (i.e. anything using sundial, for instance) I think the upgrade one is worth doubling up on. (not sure if we're allowed to go 3x or 4x or whatever, if we're even willing to risk that much).
