Is this a replacement for using VAC?

i.e can i use some software that is creating a modem like VARA, ARDOP, SoundModem and route the audio to/from EESDR3 using TCI?

I have been involved with much testing in VARA , both HF and AC and I can tell you that RigSync is horrible for attempting the VAC handoff to TCI
1) the gain control is all over the place Esp on TX, with many oddities and spikes created
2) the latency is horrible for Vara and handshaking (even with the new versions of Vara Modem, 4.5.5) again which got started due to the latency issues with SDR rigs. and Jose finally made changes after Irad, Gary, Jon and I ran many tests to try and resolve some of these handshake issues.

If you're going to run Vara with V3, the best I have been able to do and make it work 80+% of the time is use SDC for the rig emulator and then use the workaround method I posted for VAC in V3, search the form you'll find reference to that workaround.

RigSync won't cut it with that mode!
Also note that the VAC option in the newest SDC while it works better than RigSync still won't cut it for Vara because of latency issues with converting audio to and from TCI. I will say that SDC VAC is at least more stable on the gain factors and also your given the options for setting gain levels and the sample rates which RigSync have ignored to define

Thanks. I have not tested VARA but it's in the same "virtual" modem as ARDOP.

I'm also using Linux most of the time.

So if i understand you correct i can use the work around with V3 and i.e ARDOP/Fldigi to get sound in/out of the radio without installing a third party VAC software?

Before:
audio software <-> VAC <-> EESDR <-> radio

Now:
audio software <-> RadioSync <-> EESDR <-> radio ?

And software supporting TCI directly is the best option:
audio software <-> TCI <-> EESDR <-> radio

I think TCI is going to be THE industry standard for connecting Radio to 3rd party software.
Already looks like a bunch of software developers are adding TCI to their software now.

Yes i really like TCI.

I hope more people is requesting TCI for i.e Js8Call and groups.io/g/freedata and more.

Have not been able to get ARDOP to work with EESDR3 yet.

No

You still need a VAC or VB-cable for audio
But the rigsync VAC to TCI has too much latency and bad audio spikes in TX, it doesn't seem stable

By work around I mean

In the video I mention it only worked at the time with MME, It has been working with other formats since the 30122021 0.11.0 release

When it comes to low latency for Real-Time audio it’s hard to beat the ASIO driver model.

A popular alternative for applications that need low latency is to use the ASIO (Audio Stream Input/Output) model, which utilizes exclusive mode. After a user installs a 3rd party ASIO driver, applications can send data directly from the application to the ASIO driver. However, the application has to be written in such a way that it talks directly to the ASIO driver.

The problem with all the old legacy audio drivers is they were not designed to be Real-Time, ASIO is!