Are there any restrictions on using models with the following license?
"CC-BY-NC 4.0: non-commercial use only."
Unfortunately, the competition rules require that prize eligible solutions be under a permissive open source license that allows commercial use. See this section of the rules:
A Submission will be ineligible to win a prize if it was developed using code containing or depending on software licensed under… an open source license that prohibits commercial use.