I've got a Clek Foonf that needs to switch from LATCH only to LATCH + seatbelt installation in my husband's Ram. As far as I remember, the L/S seatbelt didn't automatically lock when you pull on it (haven't tried to pull it all the way out, though). Considering the locking clip in the Foonf, is it safe to use the L/S belt, even if it doesn't lock automatically? If I have a switchable locking retractor, is it better to switch it to automatic locking?