As per usual, it is not possible to do this in Epic since the game defaults to Hard difficulty.
The gimmick here is the same as the one in EBF4, random waves that gradually increase in levels. And because of that, the strategy is to adapt to whatever the game throws at you.
I was surprised to see the achievement at wave 30 and not when completing wave 30, which is something that I honestly don't rememenber if that was the case in EBF4.
Not that difficult to be honest, I mean at the end you are at the mercy of the rng but I think everything can be handled to a certain degree.