My main concern are the double sided cards, like if I see a card in english I will immediately know the effect on its back because the other copies are in portuguese? (this would be the case considering if some of the conditions are the same as the base game and the expansion add only one extra copy of it, but I dont know the contents of the expansions).
You'll definitely hit this, I'm afraid - Foresaken Lore at the least added 2 more copies of every Spell in the base game, and every expansion adds new copies of some base game conditions like Dark Pact and Blessed.
For spells I wouldn't worry about it too much, but for Conditions - and especially Dark Pacts - I'd find that a bit annoying, personally. However, it's not going to be game-breaking, and you could come up with some elaborate solution such as when you actually come to flip a Condition, shuffle it back into the deck, then get a new one at random and immediately flip it. Forsaken Lore and Strange Remnants are definitely good enough expansions to warrant some slight annoyances!