1) the filtering is completely separate from the old game "Y" key system. if you set filters, then use the "Y" key then you have effectively cleared the filter.
2) It really depends on what sort of tiddly stuff you need to avoid. For WW2, a min value of 5 would tend to filter out
most small armour. The max value can be 255 (on the odd chance you may meet a Maus or whatever
!)
cheers
Andy