Is there a plugin that does this?

The Scrap Helicopter Fix plugin does this for scrap helis. The same exact approach works for minis.
https://umod.org/plugins/scrap-helicopter-fix

This is basically the entire plugin.

private void OnServerInitialized()
{
    foreach (var entity in UnityEngine.Object.FindObjectsOfType<ScrapTransportHelicopter>())
    {
        if (entity == null) {continue;}
        OnEntitySpawned(entity);
    }
}

private void OnEntitySpawned(ScrapTransportHelicopter entity)
{
    entity.explosionEffect.guid = null;
    entity.serverGibs.guid = null;
    entity.fireBall.guid = null;
}​

If you change both instances of ScrapTransportHelicopter to MiniCopter, like I've done below, it will apply to both types of helis since Scrap Helis extend from Minis.

 

private void OnServerInitialized()
{
    foreach (var entity in UnityEngine.Object.FindObjectsOfType<MiniCopter>())
    {
        if (entity == null) {continue;}
        OnEntitySpawned(entity);
    }
}

private void OnEntitySpawned(MiniCopter entity)
{
    entity.explosionEffect.guid = null;
    entity.serverGibs.guid = null;
    entity.fireBall.guid = null;
}​​

From testing, players still die on crash. Not sure if that's something you wanted to avoid.

That's exactly what I sent him through discord, except I used

BaseNetworkable.serverEntities.OfType<MiniCopter>​

Got it from the Discord.  Thanks!