Did I get this right, the NR works on audio samples, not on IQ samples?
If it works on audio samples, as has been discussed here in detail,
it is an add-on that very easily can be added to any sort of program
Producing audio, including SDR apps.
If it works in „IQ space“ things are a little bit different, since you
can place it before or after AGC, and so on. Then it is not an extension to
Thetis itself but rather an extension to WDSP.
There is an „extended“ version of WDSP that includes additional noise reduction,
namely RNNnoise and libspecbleach (search for VU3RDD and RNNnoise), and
piHPSDR includes support for such an „extended“ version of WDSP (compile with
the EXTENDED_NOISE_REDUCTION option). It is not a big deal to include in any
program that uses WDSP (piHPSDR, linHPSDR, Thetis, … )
Yours,