I really don't agree with making tip private.
This are my reasons:
If tips are private there will be a lot of hands to pm scammers.
I was once scammed in pm but a person in room seeing the tip, made me understand that I just made a big mistake. What really happened, some impersonated a fan and then convince me to tip him for pay back, then I haven't understand pm well enough. When the transaction was done. I came to dm to see the real person. Asking him if he sees the tip because after tipping I haven't gotten a reply.
Okay what do you think will happen when it is private. That means you will fall a fool multiple times without anyone noticing and u noticing.
2. Malicious transaction. Like someone using bc for a medium to run malicious transaction without been detected on time.