But in other local boards, I noticed that most of the related merit discussion are in the main local board itself (added: even they have local off topic subboard). That's why I'm asking if there is different rules regarding this.
Each local boaards has its own rules and habits.
For example, for the french section, anything that could go in Meta, Politics, Reputation, Off Topic or the trash, I put in... Off Topic because all the other existing sections are dedicated to Bitcoin or cryptos in general. As it's not easy to create a new section that won't be very useful in the end, the off-topic section is a bit of a mixed section.