The standard design decision did not suit some players.
When creating Hollow Knight Silksong, the developers hid many secrets. Sometimes players miss them, not noticing the destructible walls.
A modder nicknamed OrionBonnie offered a solution — released "Breakable Hidden Wall Flicker." This modification makes all destructible hidden walls flicker. By default, the object flickers "gray", but the color can be changed by editing the configuration file.
The Breakable Hidden Wall Flicker mod is distributed free of charge via Nexus Mods.