"Got a handle on" is a commonly used phrase that implies a sense of understanding or control over a situation or topic. There are several synonyms that can be used to convey a similar meaning, such as grasped, comprehended, mastered, understood, acquired, assimilated, and familiarized. Each of these synonyms suggests a level of proficiency in the respective subject matter or task at hand, whether it is a skill, concept, or idea. Utilizing these alternatives can help to add variety and depth to one's language, while still conveying the intended sense of having gained a level of command or expertise.