I'm not super active on the community side of things (I basically check the discord every now and then to see the updates/patch notes and that's it) but I figured I'd toss in a comment of my own regardless since I saw the link to this thread posted.
I am a VERY slow typer. Even when I'm not typing RP-related things, even just figuring out what I want to write out can take me longer than most (ex: the "I am a VERY slow typer" took me like half a minute, because I was deciding how I wanted to open this paragraph, where I wanted it to go, etc). With that already, and now I have to think about my character on top of that? I'll often spend quite a bit backing up, deleting things, going "no my character wouldn't use that word" or "my character speaks with an odd grammar style, I should edit the word order of that sentence" and so on.
What this means is that I can take quite a while to write up a single paragraph for RP, sometimes upwards of 5+ minutes for a several-sentence reply. I get incredibly self-conscious as a result, and sometimes I'll spend a whole conversation just sitting there quietly until someone actually directs a comment at me. It's either that, or type up a response and by the time I'm done, the conversation has already moved on. It's especially egregious out in the wilderness or in dungeons, when I try to suggest we take a rest, or I ask folks to slow down so I can re-apply buffs or heal them, or telling them to hold up because I spotted a trap. Should I type faster? Well... yes, it's something I'm trying to work on. But it's certainly caused me a ton of problems in the past.
Most common is stumbling across someone in a dungeon/the wilds, they give a simple "hey" and I start typing up a proper hello and perhaps even a little emote like "They perk up and step away from the animal they were hunting, wiping blood off their skinning knife" yadda yadda, you get the idea. But I'll be nearly done typing it up and they just... run off. Often with nary a "bye". So then I feel as though I wasted both of our times and look like a creepy silent weirdo (which... okay, I play a Wild Elf who is a creepy weirdo, but that's besides the point).
Testing this out, I've already had improvements. I've already had folks stop and wait, and I get to say my piece. It's less noticeable in urban/common areas where folks are already kinda used to a regular back-and-forth and aren't in a hurry, but out in the wilds and in dungeons? My god, I actually had a proper conversation with someone the other day because they actually waited for my response because of the quacker indicator. My character regularly spends time out in the wilds rather than in town, so RP opportunities are few and far between -- so not having someone dip on me 30 seconds after saying 'hi' (or just doing the voice command "HAIL TO YE") is heavenly.
As for the complaints about abuse and whatnot... I mean, that's going to happen anyways. A while back, I got PvP'd without roleplay (against the rules, I know) because I stumbled across a sketchy individual and, in the time that I was typing up something, they jumped me... and I was literally caught flat-footed IRL because I had zero time to react. Would that person have waited if I had a quacker up? Probably not! The kind of folks who abuse and misuse systems are going to do it regardless. It's inevitable that some people are going to find any little loophole and abuse the hell out of it no matter what. If someone abuses the quackers to ambush other players... that's less an issue of the update, and more an issue of the mechanic-abuse culture some folks have.
My complaints are mainly the same as others -- fixing sizes, making it not show while typing in commands (maybe even having a "wait period" option, so you can set a number of seconds, and if youve been typing longer than that, then it shows the quacker), allowing it on henchmen/summons/etc., reducing the visible range when whispering, and so on. This is something that has, just in testing, already given me a positive experience with roleplaying, and I'd like to see it bugfixed and fleshed out.