The tuning knobs don't have much resistance so a slight touch can knock the oscillator out of tune, but I haven't noticed a slight detune or anything when both are tuned to A. I do make a lot of dissonant music though, so "close enough" is usually fine for me. Haha.
I don't have the Strong Zero VCO Core installed. Mine is still all analog, and I've found that it's a well-built and stable module. As with anything in Euro, YMMV.