Are the Checkpoint English (E1L) and English as a Second Language (E2L) tests different?

Yes. Checkpoint English Primary (E1L) (0058) and Lower Secondary (E1L) (0861) are very different tests to English as a Second Language Primary (E2L) (0057) and Lower Secondary (E2L) (0876). They test different skills and knowledge. English as a Second Language tests are not a preparation for first-language English tests.