Yes, you can keep them, but you'd need a MYO slot to have it become an official Dreadnaut. Otherwise, please keep it as a personal oc/one off without the traits or just hold onto it until you decide you want it approved.

Dreadnauts as a species/staff will not claim ownership of any designs submitted to the contest (the one made into an NPC will be 'community owned', with the only profile being on the Masterlist)