No FIKI available for 182s. Just inadvertent icing or whatever the alternative is called.
Spots can/may be fixed by running the system on the ground and wiping a cloth saturated with TKS fluid in a chord-wise manner across the spot. Needs to be below about 50 F for the fluid to be viscous enough for either dry spot fixing or general monthly exercising in my experience.
182 system consists of panels for the leading edges and struts. Prop gets a slinger ring and is responsible for the prop and the windshield. I had a T182T which has a factory hot prop and would have preferred to keep that with the addition of the windshield spray bar from the 206 install, but CAV said that would be a field approval and would take more time. So I went ahead with the stock system which worked well. This was around 2006 or so.
If the AUs are present to support a DA42, then I'd humbly recommend the T182T over the 182T as the turbo in that install is powerful and greatly increases the ability to punch up should you encounter unexpected ice; usually climbing is the best exit anyhow.