how do techpriest subtitles work in video games?
Are there interesting ways they use symbols to convey tone or meaning?
Advice on running a techpriest blog?
(Feel free to only answer part of this, I know it’s huge)
Ok, so long story short, I had typed a whole long thing out on my phone, but the draft didn't autosave (not pleasing). A few things to note, in summary: When talking to anyone outside of the ranks of the Adeptus Mechanicus, they just sound like normal people. Maybe flat and emotionless, maybe cold and calculating, but some of that also comes from their altered biology. When talking to each other, they're also broadcasting stuff through the Noösphere: images, graphs and statistics, raw data, video feeds, notifications, sometimes other things like emotional context. When you take that into account, along with the fact that many in the upper ranks of the tech-priests remove or limit their emotions, communication gets a little wacky. The authors of both the books and games for the WH40k universe try their best to present all of this in a way that we can understand, but there's only so much. It usually ends up taking the form of either code blocks or different combinations of punctuation/text styles (I prefer html-inspired psuedocode, which also fits with my persona as a low-ranking clerk assigned to categorizing the internet). However, it's your fandom. You pick something that you like. Depending on what is hooked up to their neural implants, how much their emotions are limited, and what machines they work with regularly, most tech-priests pick up their own dialects. They're all understandable to each other due to the implants, but a tech-priest who works in the engine bay of a supercruiser and one who repairs the armor and weaponry of the Space Marines who travel within will prefer slightly different terms, and might not always get along.
Tech-priests feature in almost all WH40k media, even if they're not the center of the story, both in the official books and the fanfics. Most larger library branches will have a Warhammer 40k book or two somewhere, as will the bigger bookstores. AO3 has a ton, of varying quality. Doesn't really matter what you pick, just pick one and immerse yourself in it. If nothing else, you'll get a feel for the style and tone you like and pick up a few phrases that are interesting.
A few things to note about that last bit: the Warhammer universe's primary genre is Grimdark, both Warhammer (fantasy) and Warhammer 40'000 (sci-fi). Not everything is going to be clean and polished. Also, in the eyes of the rest of the Empire, the Adeptus Mechanicus is actually a cult. Everyone else worships the god-Emperor, and even something as simple as a hip replacement after a major battlefield injury is considered a major sin against the sanctity of his will. The Cult Mechanicus, with their worship of the Machine Spirits (figureheaded by the Omnissiah), is tolerated only because of how useful they are. The entire galactic empire would collapse without the efforts of the Tech-Priests. One major contribution to society is the servitors: part machine, part living creature, they're nearly mindless drones. If it's built to aim and fire a gun, serving as a bodyguard, it will spend all of its computation power on perfect accuracy and reaction time. There's a rumor in-universe that the servitors that the Tech-Priests build are actually made using the recycled, semi-conscious forms of condemned criminals. Neither the Imperium nor the Mechanicum have commented officially on the story. Not always a nice place to live. But between servitors, ships and weaponry, the Mechanicum is the backbone of keeping the empire alive.
Sorry, I've gotten a little off-track from the original question. TL;DR: I don't actually know if there's necessarily a "right" way to get all the symbols and syntax idiosyncrasies done right. But it also doesn't really matter. The number one rule of fandom spaces, is that it's entirely up to you how you engage with them. It's your story, it's your game, it's your character, it's your blog, it's your internet. You can do what you want with them. Make up a system based off of things you like or find interesting, keep it on the simpler side to start off with (easier to remember), then build off of it. After all, even the Adepta Mechanicae don't have standardization.