If you have an effect
+1 Attack to your next melee attack
And you have another effect that turns your next single target melee attack into (diagram with 2 red hexes) do you get the +1 for both hexes?
Or if you have an attack that says 'Attack all adjacent enemies' would you get the +1 more than once?
If it says “your next melee attack” (like the Spellweaver’s Crackling Air card, although that one works for more than one attack), you get it on exactly one target - whichever one you decide to hit first.
If it says “your next melee attack action” (like the Minor Power Potion), you get it on all of them.