Richard,
I'm using the same setup as you, but with a slightly older version of Radio Caster (2.7.1.1).
The only other difference is, I'm using the DSP version of Stereo Tool and not the VST Version.
Using the Winamp/DSP version of Stereo Tool, all my settings remain after a Reboot/Crash.
Note: Verified on v9.92, and v8.54 of Stereo Tool (DSP).
Try the DSP Version, Hopefully that Works for your setup.
If not, I would recommend installing the standalone version of Stereo Tool, and output the audio to a VB-Cable, then route the output of the VB-Cable to Radio Caster.
Virtual Audio Cable (VB-Cable)
https://vb-audio.com/Cable/index.htm
Stereo Tool (Winamp/DSP)
https://www.stereotool.com/download/dsp ... taller.exe
Stereo Tool (Stand Alone 64bit)
https://www.stereotool.com/download/ste ... ler_64.exe