Well, not quite 80. More like 65 at the time. 
I do understand what you mean. But even so, you need to be careful about what you do. Don't act foolishly just because there is something you can do.
Under the old system, infiltration was mostly "train to 60%, then do whatever you want." If you return to invisible infils, you're going to return to that same "train to invisible" threshold for infiltrators.
Being careful requires doing actions just before turn change. And even that will not guarantee success if the region you are moving into is enemies region. Because if you can be tracked, nobles shall not believe anything. If you are close to the region where someone was attacked and you are only one from external realm. You are to be blamed.
Btw, my infil is 75 - 80% at both skills.
