in the params_list table, add the 'None' option:

values = {'Company Name', 'Train Name', 'Line Name', 'None'},

in the modelModifer function, change the list of actions in the 'for' loop:

if labelChoice == 0 then data.metadata.labelList.labels[j].type = "COMPANY_NAME"
elseif labelChoice == 1 then data.metadata.labelList.labels[j].type = "NAME"
elseif labelChoice == 2 then data.metadata.labelList.labels[j].type = "LINE_NAME"
else
data.metadata.labelList = nil
end
That's it!