Shifter Parts questions

[rnbrn21]

I have a few questions about some shifter parts. I just installed a TWM short shifter in my 3 and have seen some posts about some other shifter parts that I don't know much about. I've seen references to a shifter plate and shifter weights but only for Mazda speeds. Are these parts compatible with regular 3's or are they only for speeds? Also if a short shifter is already installed can a shifter plate be installed as well seeing that they both reduce the throw. Any info/advice is appreciated.