I propose an effect that would make engines explode when ignited if they are either ignited in contact with the ground or blocked by some parts.
Right now in the game, an engine ignites normally without issue even when occluded. In reality, in most cases, this results in an explosion, which is why I believe rockets are ignited some distance from the ground and Landers are made in such a way that the engine nozzle is a some distance from the ground for safe landing and safe takeoff.
This would mean a redesign of the default spawn launch pad, where it's design would be such that below the engine there would be slots or holes to allow engine exhaust without explosion. Or perhaps there can be default rocket stands and launch structures added so ignition occurs some distance from the ground.
This would make for more consideration when designing Landers and ascent stages.