Nice that days_waiting uses MAX of sent date and last follow-up, so a chase resets the clock. One small addition that pays off after a few months: a decided_at date column filled when status moves to accepted or declined. With that you can compute your typical time-to-yes, and it tells you when a quote in quote_sent is genuinely late versus just normal for your clients. Combined with quote_amount, a SUMIFS on quote_sent also gives you a quick "money still on the table" number for the weekly review.