Draq is sadly correct. I'm not sure about jaws, but if you disable browse mode in NVDA it can really help with usability. You can quickly arrow through messages like you could in skype 7.
Skype 8 on the hole has a lot of issues as far as lag goes though this could be better on jaws, and it's still inferior to 7 IMO, but you'll get used to it after a while. If only 7 was still usable...

I would be ready to help with any specific. That guide is a great resource and should answer most of the frequently asked questions. I recommend trying both Skype for Windows 10, the one built into your system, and the most often used electron version, the one you have to download. Skype for Windows 10 offers a few advantages if you can get used to some of it's weird things, like global hotkeys, which means that you can mute your microphone, end a call and so on without being focused on the Skype window. You lose the advantages of a web application though, such as browse mode or in the case of Jaws virtual cursor, which can sometimes help to obtain information quicker depending on the context. You are essentially combining 2 modes, in the case of NVDA focus and browse mode, and in the case of jaws virtual cursor and forms mode. With virtual cursor, you are using Skype as a web page, and navigating with arrow keys. This can be useful in cases like a long list of group members, since you can use your jaws key plus f to look for someone specific in the find dialog. In general, you will be spending most time with the virtual cursor off, and by default Jaws turns it off as soon as you focus Skype 8. Here, you can use it like a web app, with tab, arrow keys and other app specific shortcuts such as alt 1 to focus the list of recent chats, alt 2 for contacts and so on. You can toggle between these 2 modes with Jaws plus z.

Ah, that would be my error then. But thanks for the correction.

In spite of what guys on the FS site says, the UWP version is very good with JAWS too. I know because I use JAWS.

For NVDA users, you can turn single letter navigation on/off (with out effecting status of browse/focus mode) by using the NVDA-Shift-Space toggle. It doesn't get much talk sadly, but that command is there.

Additionally, both versions of Skype work wonderfully with Microsoft's own screen reader, Narrator.

I thought the miranda skype plugin died? It does still work? I personally tried the UWP version and with NVDA noticed it had some focus problems, would often just jump you who the hell knows where in the message history if you tabbed into it wrong while it was changing, and I didn't see a jump to last button. I'd imagine since JAWS likes to use it's webpage mode and automatic forms mode, Can you turn that off?, it would be a bit more of a pain than with NVDA, though I'd imagine doug's scripts combat that somewhat and add all kinds of useful hotkeys, which BTW skype also has a lot of hotkeys

I use the version of Skype for Windows 10, both on my laptop and on my IPhone. The only real problem I have with it is that trying to add new contacts don't work. I go to add someone's username in, the screen reader and Skype both says they found the person I'm looking for, yet it won't let me actually get to the part where I can add them as a contact. It's totally frustrating.

Referring to discord,

If on Windows, get the Canary builds. For the Macintosh, it works? Though ya have to wait for a moment for it to properly start. (Thanks to a friend of mine for the Mac confirmation.) There is a Linux client for desktops, though haven't tried any of those yet.

Both versions of the Discord mobile app are now accessible.

See, the thing I don't care for when it comes to things like TeamTalk and Discord is that you have to manage all these servers and junk. Great for group chats I suppose, but not so great when all you want is an IM program. Skype may be a pain in the rear at times, but it's usable.

Thanks for all the feedback, folks. Bearing in mind that I really only use NVDA when Jaws doesn't work, or for certain games/certain tasks, I would prefer to stick with Jaws and Skype, and that's why I said what I did in post 1. So I'm not so worried if something works badly with NVDA but well with Jaws because Jaws is my primary screenreader.