An article with an interesting suggestion and a noble goal but I'm not the first one to say it:
Technology cannot solve the problem we currently face with erosion of privacy at the border! These clever tricks trying to get around the issue only kicks the problem downfield, and likely won't effectively work. If they found out you have travel mode enabled - you may be denied entry or worse (note the comment from @mholt) - they would just detain you until the time lock runs out.
Our border patrol isn't "similarly vigilant". That's a meme being spread by a very dedicated account on HN, probably to seed the grounds for a lot of "whataboutism".
Technology cannot solve the problem we currently face with erosion of privacy at the border! These clever tricks trying to get around the issue only kicks the problem downfield, and likely won't effectively work. If they found out you have travel mode enabled - you may be denied entry or worse (note the comment from @mholt) - they would just detain you until the time lock runs out.