Navigating AML flags for new digital asset listings - specifically around source of wealth for illiquid tokens

Hey everyone, been spending a lot of time lately on the nuances of AML when it comes to onboarding clients who've acquired more obscure or illiquid digital assets, especially those outside the mainstream $BTC / $ETH. We're running into situations where the source of wealth for these tokens becomes incredibly challenging to verify beyond a simple attestation. Are others seeing similar friction points?

Specifically, when a client comes to us with, say, a significant holding in a newly launched DeFi token or an NFT collection that's seen rapid appreciation but has limited on-chain liquidity or transaction history beyond the initial mint/private sale. How are firms practically addressing the regulatory expectation to understand source of wealth without imposing an unreasonable burden on the client, or conversely, taking on undue risk? Are there specific types of documentation or enhanced due diligence processes that have proven effective in these less clear-cut scenarios, particularly for non-US or non-EU clients where traditional financial records might not easily trace back to the initial acquisition?