it is safe.....by this meathod the only admins and mods can see the registered users IP.....if there is same IP is used the 2 users...then we can understand that they are one..and also they are spammers
Other platforms have that feature. IPs are ofcourse visable to staff only so it wont have anything to do with that. It's just that untill now there has not been such feature on FM. You can suggest it here though https://help.forumotion.com/f30-suggestions-for-your-forums