Thank you for the feedback.
“Intent” is a big concept in all of this; if you do not intend on traveling to some other place when you initially register the travel then it seems to me that they can’t prove you broke a law because they need to prove that you intended on traveling where you did when you initially registered the travel. For my personal experience, I, like you, like to be flexible with travel plans; I will go somewhere on a whim because why not? I’m not on probation and the SO laws are not punishment so I will go where I want when I want. The consequence is that I have had to justify all of these unintentional change of plans to the gestapo that harasses me 2 to 4 times a year.
In some countries, traveling by a different means other than air travel doesn’t matter. For example, in Russia they know where everyone is at every moment, I believe. They have a big history of knowing the people in their country and so they are very good at tracking someone. However, the benefit of this is that it’s one of the safest countries someone can visit, aside from being one of the best countries on the planet, in my opinion.