Although I have and have used some Black Magic external tools for this, I'm also interested in simple and low cost options for Linux workstations.

In a recent article the Augustin VGB100 usb2.0 video adaper and VLC was used to record video

https://www.arsouyes.org/en/blog/2021/2021-05-17_Numerisation_VHS

Any experience here with similar A/D video adapters, quality and applications for recording on Linux?. 

Second I wonder if some lossless, compressed master video format is available for better quality before final converting with typical ffmeg?

And third, maybe a stupid question:

Is it possible to record just Audio with an A/D Video adapter, which audio record format and what quality, compared with a pure Audio adapter?  

And if so, can audio record applications like Audiacity be used?

Terje