The advantage of LEM vs SCD is this: The SCD provides a manual safety to a Glock, which is nice particularly on a SFA gun carried in an appendix holster. LEM provides a longer triggerpull travel, giving you more time to get off the trigger if you don't want to make the shot.
While there are HK LEM variants that also add a manual safety lever, the P30SK isn't one of them, at least as on orderable SKU. I don't know if HK can add one to a P30SK LEM, but frankly I think you'd likely more from switching the light trigger rebound spring to at least the medium-weight one.
LEM is aimed primarily for LEOs involved in threat management with a drawn weapon, it's my impression that the SCD is aimed more for the personal safety of the user, particularly when re-holstering.
If you peruse several of the LEM threads on p-f, most will establish that there's a bit of a learning curve to LEM. Organizationally and individually, I think there's a huge benefit to it, especially when compared to a short trigger travel, relatively light/soft breaking SFA, particularly like the SIG-Sauer P320/P365. A Glock has a harder wall at the trigger break point.
I'll recommend Darryl Boelke/Dagga Boy's superb discussion of LEM and comparing it to other actions.
https://pistol-forum.com/showthread....t-trigger-quot
Best, Jon