Mod VCF to even out self-oscillation onset

I notice the Anushri VCF circuit seems biased towards self-oscillation at higher frequencies. Within the constraints of the design, it is possible to improve this? I’m not expecting musically-accurate cutoff tracking, just allow more of the cutoff range to be near self-oscillation for maximum impact.

I appreciate the filter gets a lot done with a low parts count. I will have control over the resonance via a digital pot so I can compensate to a degree in software.

Things to try: playing with R15 ; changing the values of the Zener diodes ; a little capacitance between pins 8 and 9 of IC5.

Changing C14 to 100 pF seems to have improved the self-oscillation the most for me. Thank you for your reply!