Personally I'd remove Rs3/OSRS item trading sections instead of making it a submarket. It's literally the same as buying/selling GP as RS3 Partyhats and people do that in the buying/selling gp section too. It's a duplicate but more useless thread. Also it's quite dead.
Name Market deserves it's own section so newcomers can find it. I can see multiple subcategories spawning out of it like transfer services too. It's also annoying going through the item trading section to go to the name trading section because the way it is now makes it relatively hidden.
Most people that don't trade names would feel indifferent but it's the only reason why many others and I use Sythe. I also feel the same as Alexandre after participating in this community for quite a bit.
Full support, it would suck to prioritize a dead item trading section over the possibly growing name sub-community. Having it hidden will kill it further over time.