With regards to MAGI, can states that want to have a "rounded" number for their eligibility standards do so or must they stay with the converted standards?

Yes, states can adjust their standards within certain limits established by law.

States can adjust both their adult standards (e.g., for pregnant women) and their children standards, as long as they do not reduce eligibility levels below minimum standards established by the law. CMS can advise states of their options.