Ben and August’s Extended Editor (BEEMOD) & BEE2
When you say, "the mod is nearly complete," do you mean like a few days, or more like a few weeks? I'm just real anxious, as your mod appears to be awesome.
the end of the month
I'm making my own editor mod, but very different to yours. Mine is a Style Changer mod that changes the style of existing elements, walls, and elevators, rather than adding new ones. You just run my StyleChanger.exe to choose a style from: 1950s, 1960s, 1970s, 1980s, Portal 1, Destroyed, Behind The Scenes, Evil Wheatley, or Clean. Then any map you preview or compile will be in that style, complete with textures, entrance and exit elevators, testing elements, ant-lines, voices, etc.
It's nearly finished.
My mod also includes replaced vbsp.exe and vrad.exe that add the following features, which can be activated by adding codes to comments in the editoritems.txt file: removing the entity limit, automatically packing certain files, fixing the bug with messages not being sent to barrier hazard models, replacing wall/floor/ceiling textures, changing signs and antlines, changing barrier hazard and barrier extents textures, changing the skybox, changing goo into bottomless pits, compiling previews with faster lighting, and including the entrance and exit in the preview if you press Ctrl+F9. And of course it can select which editoritems.txt file to use.
I don't know if any of those features are useful to you, or if there's some other features you want added that require automatically changing the .vmf file before it's compiled.
I can also get silver Reflection Gel working and looking right, and have purple Adhesion Gel, both in the same PeTI map, and with all the other gels still working. The Adhesion Gel doesn't do anything different from the Reflection Gel though, just looking different so you know to use it on cubes to stop them sliding off Propulsion Gel. It requires some materials and particle systems to be automatically packed though.
I don't know if you want to collaborate together or help me make it so my style changer is compatible with your mod. Or if you want me to help finish your mod for you, or whatever.
Wait, so broken catwalks, old indicators, and brown grating for the cave style? Wow! And wait, you're going to add reflection gel to your mod? wholeh carp! though it does sound hard to use...
Also, for the BTS style, will that change the lighting to be BTS like and will we be able to place those huge black squares with things on them?
The style changer idea sounds very cool. How did you manage to change the barrier-hazard textures? I've been trying to find a way to do that for a while to add a new type of fizzler (defined by placing a normal fizzler, then some dummy prop at one edge).
if I'm not mistaken he uses a custom coded vbsp.exe to swap textures(as defined in the comments of the editor items.txt), then call the original vbsp.exe
EDIT:
here is another sneak peak of the BEE
I agree, looking sharp Ben! 
Very artsy screenshot.
And I assume the anti-trigger to be like stepping off a button or a handbutton timer finishing, making an element collapse/restore again after the trigger. That's it, right?
PS: I still don't get what the point of the slightly elongated panel bridge is, but whatevs. Maybe it's usefull in one or two situations. 
Maps in Development:
[spoiler]- Penrose 04 (on hold)[/spoiler]
Maybe if you're trying to attract attention to one panel when there are many?
Maybe if you're trying to attract attention to one panel when there are many?
That sounds slightly ridiculous as its only purpose though... Why not just draw a little smiley, or a pink heart or something on a cube if you want it to seem special, then? See, that's just as proposterous. 
(All joking aside though, that wouldn't seem like a fit reason for its existence here.)
Maps in Development:
[spoiler]- Penrose 04 (on hold)[/spoiler]
The slightly elongated panel bridge was made by Valve and comes with the puzzle maker already. Have a look in your instances/p2editor/ folder and you will see it there. That's probably why he added it back in.
I don't know what it's for. Maybe it's for using over goo?
And I'm changing the fizzler texture like he said, but I haven't implemented anything to change the type of fizzler, only to change how it looks. And I fixed the bug that stops the fizzler models from receiving open and close messages.