A fuse does not protect electronics, only transformer and wiring. The TVS is needed for electronics protection.
An in-fuse on the hot side from transformer to track will blow with a derailment, hence no power to the track, hence protecting the modern engine on that track.
Like I said in a previous post, I successfully used postwar ZW’s to operate my TMCC trains with no issues. I used 10 amp fast blow 2 mm glass fuses and never blew an electronics board on an engine, hence I protected the engines if something went wrong.
