I’ve asked in another forum about this last year (conclusion there, no issue in reality, you’re holding the thing in your hands, standing in a room, so you’re basically providing a way for the static to discharge in addition the to the vacuum itself) and also paid attention to static on my vacuum.
When I use this long plastic tube (to reach shelfs, ceiling etc.) it seems theres quite some static building up, always large amounts of cat fur stuck to it. But with the little brush thingie, not much static seems to build up.
Also, the vaccum is not touching parts inside the machine, only the case anyway.
I usually use a brush to clean my synths, holding the vacuum so that it catches the dust I brush off. Better due to encoders etc., but I used to just vacuum them for years.
I’ve also used the vacuum inside computers and other electronics, never any failure.