DHS does not deny strong-arming tourist into letting them into his phone, only that agents sent him home because of a meme
The story circulating online — first in Norwegian newspaper Nordlys and then picked up by British tabloids — claims that during Mikkelsen’s encounter with the Department of Homeland Security, agents took his phone and found a meme depicting Vance as a bloated, smooth, bald man staring off into the distance.
Mikkelsen claims that the officials threatened to fine him $5,000 or send him to prison for five years if he refused to provide them with his phone password. The tourist ultimately agreed to hand over his information, allowing agents to look through his phone.
The reports picked up enough steam in headlines and on social media to justify CBP putting out a statement denying parts of the story.
I agree with activating those options but due to timers preventing you to make another try starting after the 5th incorrect entry it will take at least 1h 21m to enter your PIN incorrectly 10 times. The last timer alone is 60min. So this unfortunately is not a quick way to wipe your iPhone in this scenario.
I suspect they will not wait 60min to let you enter the a wrong PIN for the 10th time if you even get that far. Much more likely they will confiscate the device to clone it in order to have unlimited tries for brute forcing if they really want to access your phone.