Yeah, it's about time this issue is seriously looked into, even having max inventory on main and dual classes doesn't fix the issue.
Why even spending elcyum to get these extra inventory slots if it's uselss in the end...
When pretty much every player in the server is facing the same problem, then it should be adressed (especially since it really seems like a poor programming job to begin with).
For a player with decent gear, all the equiped items, consumables, various runes and other various useful items already makes you at 90 or more items. So it means you have to to get rid of what's not strictly necessary everytime if you want to be able to change class freely. That's pretty ironic when you actually have more than enouh space to store everything.
That would be great if we can be freed from this after so long, that' would be a seriously great QoL improveent for the game, so please, Juji, talk with the dev team to do something about this (without causing server crashes )!!