Editor updates:The SuperLemmix Editor is based on the NeoLemmix Editor, and uses the same codebase. It's mostly the same, but here's a list of everything that's changed so far:
Custom Piece Move: Pressing Alt+Arrows now allows pieces to be moved a custom amount, which users can set to their liking in the F10 Settings menu
Horizontal and Vertical Drag: Pressing Ctrl+Shift then dragging pieces allows them to be dragged Vertically (along the Y-axis only). Pressing Ctrl+Alt then dragging pieces allows them to be dragged Horizontally (along the X-axis only)

Freezer, Grenader, Spearer and Timebomber added to skillsets

Kill All Zombies talisman added

Wider theme/styles dropdowns for easier reading

Some of the fields, buttons and labels have been re-named slightly (their functionality remains the same)

"Clear Backgrounds" button has been moved to the piece selection area

"Tools" and "Options" menus have been condensed into one (labelled "Options"), so Snap-To-Grid now appears here

Play Level and Validate Level have been moved to the File menu, and Validate Level now has its own hotkey (Ctrl+F12)

Stoner support removed

Auto Screen Start is now unchecked by default - the plan is eventually to set this back to checked by default, and automatically uncheck it if the user edits the screen start values
Wish list for the future:

Make "Lemminas" another type of lemming (like Zombies, Neutrals) which can be added to levels alongside regular Lemmings (this will also need player support as well, obviously)