I installed the  Dollars Markerless MoCap today https://marketplace.reallusion.com/dollars-markerless-mocap
which seems very promising at least for hand gestures.

The tutorials say it can be used in parralel with LIVE FACE, but only when using a virtual desktop camera through
another plugin for "OBS studio".

I havent tried that, because it will definately have LATENCY issues. One way goes through the LIVE FACE App
directly, the other (for the Dollar app) through the OBS plugin, OBS + The Dollar Plugin + The Dollar Software.
Everyyone can imagine how thats gonne turn out latency wise.

Though i want to hear your opinion and in special, if anyone went this way before (through OBS and LIVE FACE together) ?

We have made a video to show the latency, sir,
https://youtu.be/6hYFLyZlgMY

The tester opens the mouth and raises the hand at the same time.
The time difference between the character opening his mouth and raising his hand can be observed to understand the latency.

Please notice that LIVE Face isn't designed for motion capture, and using a mobile device for motion capture in Dollars MONO needs extra effort, so we just show the possibility here.
Ror optimal results, we recommend using Dollars MONO with a webcam. This setup is not only easier to setup but also more effective at capturing larger portions of the body.

Please notice that LIVE Face isn't designed for motion capture
Are we talking about the same app ?
https://apps.apple.com/de/app/live-face/id1357551209

If we forget about the latency for a moment, i used my Iphone with Droidcam and your app and i must clearly say
RL Live Face performs much better on Face capturing. Have in Mind that Live Face uses the Depth abilities of an Iphone camera
to achieve a more accurate capturing as with s webcam. Webcams may be good for basic capturing, this is (my guess) why RL never
released a webcam Profile for Iclone. As far i understood the depth imformation of the iphone cameras are an important factor here.For users who already have a webcam , your app is of corse a nice solution for basic capturing, but could it meet the accuracy of Live Face
after whats been said above ?.

Please note fo any fruther discussion on capturing techniques i would not be enough of an expert.

Yes, it is designed to do "facial motion capture" which is different from body motion capture.
from its description,
---
LIVE FACE APP for Cartoon Animator and iClone, allows you to do instant facial motion capture on any 2D and 3D characters.
---

If we forget about the latency for a moment, i used my Iphone with Droidcam and your app and i must clearly say
RL Live Face performs much better on Face capturing. Have in Mind that Live Face uses the Depth abilities of an Iphone camera
to achieve a more accurate capturing as with s webcam. Webcams may be good for basic capturing, this is (my guess) why RL never
released a webcam Profile for Iclone. As far i understood the depth imformation of the iphone cameras are an important factor here.For users who already have a webcam , your app is of corse a nice solution for basic capturing,

No, FYI, LIVE Face doesn't use depth information to do facial capture, you can easily confirm this by blocking the depth camera while doing facial capture, or facing the camera to a video on the screen.

but could it meet the accuracy of Live Face after whats been said above ?.

No, we have never said we could beat LIVE Face. And it's possible to use LIVE face to capture the face while using our software to capture the body. We have a video showing how here, https://youtu.be/FDX_7RMFk3Y

Back to the topic, there are two points of us,
1. dont' use LIVE Face to do motion capture,
2. use our software with a webcam if you are not familiar with it