Tbh, if you're that nervous about crossing the border with data, I'm sure you could find other ways to use the internet and decent encryption (behind multiple layers and/or people with a Deadman's switch if you're really paranoia and worried a judge will force you to unlock the precious 4mb worth of information) to protect your data when crossing a border.
Or probably even safer if you're talking about just 4mb of data: send it from a random address in one country to a postbox in your destination or something by post. Tampering with mail carries a pretty heavy fine in most countries, chances a random postman opens a random envelope to a random address abroad are basically non existant. Security through obscurity.
I like reading about infosec, but some of it borders on absolute paranoia tbh :)
To play advocate of the devil here (I can feel the down votes and Foss brigade already coming) : I can understand their logic. Their whole business is fucking ads. These apps bypass their entire business. Count yourself lucky they've ignored them this long.
YouTube premium is actually one of the only subscription services I use. My entire family gets ad free YouTube + YouTube premium. The amount of YouTube we watch and music we listen... 100% worth it. + a premium view supports creators more than a free view, so I even get to feel a bit better about myself. (I watch too many different channels to make it financially viable for myself to send them all a dollar/month through means outside of YouTube)