KYC/AML for Institutional vs. Retail on New Platforms

We're building out a new platform for digital asset trading, primarily targeting institutions but with a retail on-ramp planned down the line. The compliance lift for institutional KYC/AML is, as expected, a beast. My question is, how many of you who started institutional-first found yourselves rebuilding huge parts of your compliance stack when you introduced retail, or were the foundational elements robust enough to scale with minimal re-architecture? Just trying to avoid a costly refactor down the line after we've burned a mountain of dev hours.