'Instako' is a command for Magma, and I was wondering if there's a command on Essentials that does the same job?
yes. here it is.
/remove on (Gives access to delete entities (structures and AI entities) upon hit)
/remove off (Revokes access to delete entities (structures and AI entities) upon hit)
/removeall on (Gives access to delete entities (structures and AI entities) upon hit. If the entity is a structure, it will destroy all conntected structures too)
/removeall off (Revokes access to delete entities (structures and AI entities) upon hit. If the entity is a structure, it will destroy all conntected structures too)