I only have to deal with it by watching the saving throw of the victim and making certain the behaviour is appropriately adjusted to account for the magical effect while it is active. In short, it's about as onerous as a NPC effect on a PC.
I confess in 1e, one of my tactics for first meetings is to cast Charm Person on suspect new party members and then treat them as good friends while the spell is in effect. No abuse, provide aid as necessary, only ask for necessary help, always bargain fairly, etc. It is a way to short-circuit the whole "let's learn to trust one another" and reduce "I stab the party in the back" set ups. By the time the spell wears off days, weeks, or months later we're solid companions. When confronted about the magic, I ask the victim to name one time I took advantage of the effect and explain it was simply insurance against ulterior motive since we didn't know one another.