He did not play single high at any significant clip in college.
This is from Dane Brugler:
SUMMARY:
A two-year starter at Washington, Molden played a nickel role in head coach Jimmy Lake’s five-man starting secondary, lining up primarily vs. the slot receiver while also seeing reps as a single-high safety. He was part of a secondary in 2018 with three future draft picks (Byron Murphy, Taylor Rapp, Jordan Miller) before announcing himself as a legitimate NFL prospect as a junior in 2019, leading the team in tackles, passes defended and interceptions. With his reactive athleticism, Molden quickly processes pass/run and stays coordinated in zone and man coverage to make plays on the ball. While scrappy and smart, you wish he were longer and faster to provide the versatility to play outside. Overall, Molden’s lack of ideal size, length and twitch will be a disadvantage at times vs. NFL skill players, but his instincts, competitive nature and read/react skills are tailor-made for a starting nickel role who shouldn’t leave the field (defense or special teams). GRADE: 2nd Round (No. 45 overall)