It occurs to me that the primary reason for most static build-up in tooling like this is the use of a dust extractor. The small particles of wood swirling against hoses (which are good electrical insulators) builds up localized static charges. When some of those build up enough potential they can find each-other and eventually arc through to the nearest lower potential area. This is often a human standing on the ground touching metal parts of the tool.
As I mention in my comment, Festool has (AFAICT) built-in static dissipation built into their dust extraction systems. If you have modified that, or it is not quite connected properly, you can still get shocks. The issue here is that the entire ducting system needs to have a way for the localized charges to bleed off. I'm not sure how the Festool system manages this, but some people have had success by encircling the ducts through their system with lower gauge copper or aluminum wire, all leading in a continuous circuit to some lower potential area (which we can call earth or ground, but really is just lower potential than the large air-plastic capacitor hanging from the ceiling).
There is at least one well-known wood-working Youtube channel where this DIY static dissipation system is described.
Like I said, many dust extraction systems already have this built-in, though having more than one path for these high potential areas to bleed off to lower potential areas that are not the operators hands might be recommended in this case.
After all, being surprised by shocks while operating spinning edged tools could be considered a safety issue.