Lessons learned buying cash-heavy businesses?

I'm looking at two deal where a significant portion of the seller's stated earnings sits off the tax returns via cash receipts. Bankable SDE is roughly half the claimed net but asking is anchored on the cash-inclusive number. I'm curious about how to structure around it without paying for income I can't underwrite, finance against, or may not be able to verify in QoE. Looking for war stories from anyone who's closed (or walked from) something similar. Specifically: - Structure: Seller note on standby? Earnout against post-close verified performance? Contingent payment tied to bank deposits or some other proxy? What terms actually held up — and did the seller take them? - Pricing the cash component. Haircut multiple, refuse to credit it at all, or pay full freight on deferred terms? Where did your deals actually land vs. ask? - Tells that the story didn't hold up. Beyond the obvious lack of records, what were the signals in the conversation, the financials, or the seller's behavior that told you to walk? More broadly looking for general outlook on this type of business. Presumably they're being bought and sold and folks finding a way to make it work but curious what it takes and what are the watch-outs.