I’m wondering if adding these options afterward could cause any side effects. Does anyone know?
Changing content.salt will make Kirby re-generate all image version/srcsets. So you want to clear the media folder afterwards. Re-generating all this image version on a per request basis can cause high server loads, depending on how many image versions are requested and how large the source image is.
Changing cookie.key i assume will invalidate every session and by this de-authenticate every user? This is just a guess so would wait for confirmation by Kirby Team.
Also changing content.salt will change your image, PDF, etc… URLs.