This isn't an update so much as it is a completely different level! It's also probably (I'm guessing) way too late to submit levels, so this is not an official entry but it does satisfy rule 1, so consider it a bit of fun

EDIT: If acceptable, I would prefer to submit this as my entry rather than The Diving Area, which is turning out to be not as simple as I wanted it to be. Let me know if that's OK.

Very exciting update! I've made a quick level and tested the following features:

1 > Added support for copying/pasting terrain groups between editor instances - Tested this with some grouped terrain, works a treat. Great feature!
2 > Added support for editing (not merely preserving) the direction and speed of moving background objects - Not tested (not entirely sure what this one means)
3 > Added support for opening levels via command line / drag-and-drop (this also allows configuring Open With with the editor) - Works brilliantly. I did a happy dance, and then spent the next few minutes opening levels just by clicking them, or by drag-dropping into an open Editor instance, just because we now can!
4 > Grid status indicator added in lower-right of level area - Works for selected terrain, objects, and sketches, but doesn't show cursor location when nothing is selected (which I'm guessing is the correct, intended behaviour). Do the co-ordinates refer to the top left corner of the piece?
5 > Quantity of normal, zombie and neutral lemmings is now displayed next to the lemming count input box - Tested: I made a level with 3 hatches and 4 lems. Whichever hatch is drawn first will spawn the extra lem, so order is important for this feature
6 > "Snap to grid" option added to menu bar - Not tested; I don't use the grid, so this feature is probably best tested by someone who uses it extensively
7 > Fixed a bug where backgrounds would sometimes not display correctly - Not tested
8 > Fixed a bug where the group / ungroup piece options in the Edit menu were non-functional - Tested; works fine
9 > Fixed a bug where trigger areas were shown for object types with no trigger effect - Tested; works fine
10> Fixed bugs that caused piece locations to "jump" when selecting them if the grid is enabled - Not tested (see item 6)
12> Fixed a graphical bug with nine-sliced objects - Not tested; I haven't yet had a chance to play with nine-slicing properly, but I no doubt will very soon
13> Fixed the bug where the color of the Jumper skill count input box doesn't change like the others do based on skill count - Oh yeah! I'd never noticed that before

+1 for zoom to cursor. EDIT: It seems to do this anyway if no piece is selected...

Interesting tileset. I made a very quick level using it, and I'd say that without direct side-by-side comparison, it's mostly identical to orig_pillar. The most obvious differences are the water, the wider variety of steel pieces, and the more-diagonally-slanted staircases.

One thing I noticed is that in the Editor, under "Theme", it's listed as "l2_classic", whereas all the other L2 tilesets are listed as "L2 Whatever". I'm not sure how to change this, but it might be good for them all to be grouped together.

I'm getting the error message "cannot terminate an externally created thread" pretty much every time I load a level form the menu. Restarting NeoLemmix usually helps. Also, the message doesn't seem to be appearing between levels (i.e. once the game has successfully loaded)

EDIT: OK... already revised it! It's much neater now.

EDIT 2: Revised it again following a backroute solution by ericderkovits, this one should be the final version. Should be...

EDIT 3: Uploaded again without the time limit, which is actually not needed to fix the backroute. It's exactly the same otherwise.

Revision following kaywhyn and ericderkovits's backroutes. I've put the time limit back in and locked the release rate (the latter is something I don't like doing if I can avoid it, so if I think of another way to fix the level I'll make another revision).

I've abandoned that idea for now since it's only possible to add 10 people to the group. I was originally going to add everyone on LF Discord (with the idea being that people could simply leave if they wanted to, but everyone was invited to begin with, rather than having an "exclusive" group) but when it got to 10 people I realised I couldn't add any more.

That being the case, it probably does make more sense to see who would be interested in taking part in a video chat at some point, and then either scheduling it or simply adding those people to the group and calling them when everyone's online at the same time.

No problem. Your new chair has been put together, but all your other furniture has been taken apart.

I wish I had a pet ostrich.