Variable voltage glitches

No, that’s not possible for ChipWhisperers. You’ll need to build something external, but you can use the ChipWhisperer to time the glitch for that. For example, you could do something similar to https://toothless.co/blog/bootloader-bypass-part3 where you use a multiplexer for the glitch, replacing the FPGA with glitchout from a ChipWhisperer.