So a couple of more weeks turned into 9. But who's counting?
I'll summarize most of what's been going on in one word: school. But I'm pleased to announce that the AC10/12 is ready to go! I just need to apply the mod to the weathered version and it will be ready for publishing!
Work has already begun on the next part of the "Final Phase" of mods for the American steam locos. I'm tackling the combined Big Boy and Challenger final round of mods now. This one promises to be more extensive than my previous mods for either loco and will take me some time to finish. Let me explain what's projected for this round of mods:
You will obviously need both payware versions of the Big Boy and the Challenger from steam for either mod to work, as parts of the Big Boy mod will reference things in the Challenger pack and some parts of the Challenger will reference things from the Big Boy pack, and I don't mean sounds. Here's the reasons for the referencing across the packs:
1) The Big Boy tender has always been an issue. The coal animation, even after DTG updated the loco, still makes the loco look like it's about to run out of coal.

For me the devil's in the details, and no matter how I've tried to fix it, I just can't figure it out. So for the modified Big Boys, they're getting the Challenger's coal tenders, renumbered as needed. The Challengers and Big Boys pretty much had the same 14-wheeled tender, and it looks better. There will be no need to copy GEO files as the necessary aliases have already been made in the tender's bin files.
2) The Big Boy, as it is straight from the store, is set up to be a coal burner, as it should. However, the original pack was released years before UP announced its intentions to reacquire a Big Boy, convert it into an oil burner, restore it to working order, and use it in excursion service. There have been scenarios made featuring 4014 in "restored" condition, but those scenarios feature the engine with a coal tender, still set up as a coal burner. The devil's in the details, so I'm taking the Challenger's oil tender, aliasing all the blueprints, renumbering it to 4014, then I'm making a special variant of the original Big Boy which will be designated as "Union Pacific 4014" in the scenario editor. What's special about this is that I'm swapping the original cab view out of this Big Boy and replacing it with the Challenger's cab view, which is set up for oil burning, so not only externally will it look like 4014 once restored, but on the inside it will look a bit closer to what it will once it's converted to oil burning. I've already got this special variant working thanks to A TON of aliasing between the Challenger and the Big Boy pack and so far no major problems have come up. 4014 also now has its own unique thumbnail image in-game on the engine selection screen and on the loco information tab. 4014 also has its own loco information tab with information more specific to 4014.
3) The Challenger Pack comes with 3 variants of the 3900s: a black version with smoke wings, an overland grey version with smoke wings, and then the "standard" version without smoke wings. All engines are set up for oil burning, yet there's a coal tender included. After reading the above post about 4014, you can assume that I'll be switching the oil-burner cab view out of the coal-burning challengers and replacing those with the Big Boy's coal-burning cab view, so now the "standard" challenger will not only externally look like a coal burner, but on the inside it will also look like a coal burner, as it should. Seeing as how the 4014 oil-burning variant is working, I imagine this cab view swap will also work just fine.
4) There will be 3 variants of the Big Boys: the class 1 (Nos.4000-4019, 4884-1 on the scenario editor menu), the class 2 (Nos.4020-4024, 4884-2 on the scenario editor menu), and the restored 4014. There will be at least 4 variants of the Challengers: both smoke wing versions, the standard version (4664-3/4 on the scenario editor menu), and the last development of the Challengers (4664-5 on the scenario editor menu). Every member of each class will be represented in one way or another, so numbering schemes are going to be overhauled, with the front engine set having the prefix B, the rear engine set retaining its prefix X, and the tenders retaining their prefix C. This is so that each part of the engine will have its own number and the timetable editor won't freak out because 2 engine units share the same number and are right next to each other, returning a static consist clash and making marshal commands easier to program. The only engines that won't be represented are the original CSA 1 and 2 since those have never been released for Train Simulator.
So pretty much because of tender swaps and cab swaps, you will need both payware models for either mod to work properly.