What will break Frontend component updates in 2026.6 ?
Frontend updates very often gives me headache.
What will happen this time?
Depends on what custom plugins and perhaps UIX styling you use. Most affected is custom-sidebar. Other than that not so much. I have noticed that the menu buttons have no top margin now (just left/right/bottom), so all just a wee bit tighter, you may not even notice. I only noticed when UIX visual tests broke, and it was just this change.