I suggest adding several blocks with a level requirement for players to enter. This increases the level of entry for bots to spam players with RMT messages which will reduce the amount of bots players may see.
Why it is needed? I know many have expressed frustration about bots in the lobby. I have blacklisted and reported so many that I had to clear my blacklist once because it filled up (500 users). Blacklisting and reporting is just not a good countermeasure because it requires players to go out of their way to do so, plus the blacklist limit means it is not sustainable. The lobby has so many important features that just going somewhere else is not a solution because you have to go back to the lobby once in a while, meaning getting your chat flooded by bots.
How does it mitigate? Adding a level requirement like level 75 to a block will increase the barrier of entry for bots, making them work harder to create a new account/character for advertising. Currently, if a bot account get banned, they can just create a new one immediately and continue the spam. By adding a level requirement, bots have to spend more time grinding their character to a high enough level to get into these new blocks to reach the active playerbase (I'm assuming active players will be high level). This should reduce the number of bots the active players see, making the player experience much better.
What problem can it cause? I suggested a level requirement because I want a time gate to lengthen the startup time for a bot, but not too difficult where it locks out the other player base that are not high enough level yet. The problem I can see this causing is the game's first impression for new players where they jump into the game and are immediately spammed with RMT bots with very few actual players to interact with (since they would be in the level-locked blocks).
Can this be done? In JP, they have an "experts" block system which only allows players who have completed a certain achievement to enter. I wouldn't really suggest that in PSO2 Global since that could create more "elitism" attitudes and divide the player base. This system could reused to have it be a level requirement instead.
This is ONLY a mitigation strategy, not a solution. The bots may be able to automate leveling up new characters, but this should increase the time and effort to advertise to a majority of the player base. By increasing the barrier, the cost/benefit scale may tip over to where less bots may show up because it is not worth the effort. The current system just makes it way too easy for bots to restart their RMT business after being banned.