Experiences with liquidity providers for illiquid commodity contracts?

Been looking into expanding into some of the more niche agricultural contracts, specifically those with lower daily volumes compared to your typical corn or soy futures. My current prime broker is good for the majors, but their fills on anything outside the top tier start to widen out significantly, or I get partials that make managing position size a headache. I'm exploring alternative liquidity providers or even prop firms that might have better aggregation for these specific instruments. The question isn't just about headline spreads, but actual execution quality when you're trying to move anything more than a few lots. Has anyone found a provider that genuinely excels here, especially concerning payout reliability on profitable trades without excessive KYC/AML friction during the onboarding for these more specialized products?