When I travel to Menelaus an infinite rain of crawlers start to spawn under my spaceship. It is normal? I'm playing the last version of the mod

Fixed in 1,15, aparently there is a ENtityxPlacementRegistry

Thanks

For seome reasons vanilla let therm spawn mid air. I dont know why (its kind of funny though)

I think you just got lucky. It didn't happen for me.
IMHO, use the obscure 'move the ship interface' and or light it up.

Free string!