In combat it is a one shot bonus and out of combat the limitations are less (though you can not cast message to tell your allies what you see) At higher levels there is the greater invisibility spell and the monks empty body that allow them to remain invisible even after mak...
No where in my whole lengthy three paragraphs did I imply that you (or anyone else) must take what I was saying as gospel, I merely made a suggestion. Again, having played every edition of the game for nearly 40 years now, plus many other RPG's...