I want to allow increase the amount of items that can be filtered  on

Industrial Conveyor

try changing the server parameters.
server.conveyormovefrequency
server.maxitemstacksmovedpertickindustrial

no those parameters only change the amount they transfer move etc. not the number of itens on

Conveyor
this is what I'm referring to.
You cannot add more items here. I haven't found any parameters to change this