we could explain our customers that the main difference between these two parts is the fixed-frequency operating at 260 kHz for NCV51411DR2GOSCT-ND and 520 kHz for the Non-stocking CS51414EDR8GOSCT-ND.
Please check the two datasheets on the related product pages following the links below for a full feature comparison:
closest alternative for part CS5141 4EDR8GOSCT-ND as IC REG BUCK ADJ 1.5A 8SOIC from onsemi for our customers is:
NCV51411DR2G as very similar IC REG BUCK ADJ 1.5A 8SOIC.
Please review the datasheets to ensure the alternative will work for your application.