Why not instead of

Our wayfinder-menu contains ~200 Links which lead to a bad speed-perfomance.

Therefore we now use wayfinder cached like this [[Wayfinder?]] and as far as we can see everything works well.

So why it is recommended to use Wayfinder uncached like [[!Wayfinder?]]. Are there any reasons for this?

Gerdi

Have a look to this: http://sottwell.com/how-snippets-work.html
It’s referring to Evo, but some aspects have not changed.

If you change the permissions on any resources in the front end with a Resource Group Access ACL entry and forget to flush permissions, restricted resources may show up for people who shouldn’t see them. Similarly, deleted resources may still show up in menus.

As long as you remember to flush permissions whenever you change permissions and clear the site cache when resources are added or deleted, however, you should be able to use the cached version of Wayfinder without causing any trouble.