I am working on vol surface modeling for cryptocurrencies and generally find that SABR calibrates to the vol surface on ETH better. I know that eSSVI ensures arbitrage free surfaces and therefore that we sacrifice a bit of goodness of fit for it, while SABR isn't guaranteed to be arbitrage free when interpolated, but even by adding safeguards and penalties to SABR to push the general surface towards non-arbitrage, which should limit flexibility, i find a better fit than eSSVI while having no cal