Currently guest/collab difficulties can do almost anything with difficulty name, guest mappers decide if they want to show possession or mention name on their GDs/collabs, but also free to avoid any kind of credit and mentions.
( e.g
)
Meanwhile set host must not show possession of their own name which creates unfairness in that regard and allows such naming scheme to exist

but disallows

Changing the rule
Also on a side note we already have system that shows owners on all difficulties on site which is handled fairly well and additionally i can ASSUME eventually lazer would finally show owners on song selection screen properly, so sooner or later there won't be confusion regarding any kind of naming from player's perspective as well.
( e.g
Meanwhile set host must not show possession of their own name which creates unfairness in that regard and allows such naming scheme to exist
but disallows
Changing the rule
A beatmap host cannot indicate possession in a difficulty's name. (e.g. Beatmap Host's Insane). Conflicts caused by beatmapping multiple songs with the same metadata and collaborative difficulties are the only exceptions. Guest difficulties, however, may indicate possession with its creators' name or nicknameand merging it with existing guideline with slight rewording
Difficulties may indicate possession with its creators' name or nickname. names indicating possession of a difficulty should be consistent between multiple beatmaps. Varying nicknames for one makes interpreting who created a difficulty ambiguous or misleading.would give more fairness to the situation and there won't be any downside in indication of name. So at the end of all, set hosts and guest mappers would have equal allowances in difficulty naming.
Also on a side note we already have system that shows owners on all difficulties on site which is handled fairly well and additionally i can ASSUME eventually lazer would finally show owners on song selection screen properly, so sooner or later there won't be confusion regarding any kind of naming from player's perspective as well.