As you can see J, there really isn't one good answer. Everyone has their own idea. So really, it is up to you. You need to do what you feel is right, based on the situation, how you feel, how competitive you are, etc
In most cases, these are putts under 4 or 5 feet. If you have a partner getting mad at you over a 3.5 footer that you conceded in an Alt Shot match then you need to find a new partner. Alt Shot is typically done for the social aspect of the game and more about having fun and meeting new people than it is about who wins or loses. If pard or opponent gets mad, just tell them to chillax and enjoy the game, it's a 3 footer ffs