The Inventory counts what you never used
The idle line now says how many of your idle items were never used in any chat, not just in the range you picked.
The Inventory's idle line, such as "12 idle", now adds how many of those were never used in any chat at all, for example "12 idle · 9 never". Those are the safest to take out.
The figure only appears once Bandicot has read every past chat, so it never claims "never" from a partial count.