I still do an old-fashioned Excel sheet to calculate.

So, how does Gemini determine the exact amount of each line on the folio that's eligible to earn points? When I have a dining or spa charge or parking charge, the line on the folio is typically inclusive of the taxes, Resort Association Fees, gratuities, etc. Only the base amount before those charges is eligible. Does Gemini just estimate the amount of the included non-eligible spend, based on your past tipping practices and what it knows about the fees and taxes charged at that particular property?

I just completed a stay, where they got my points wrong. They missed giving me points on all of my dining charges. Fortunately, they also missed deducting for the amount of points I redeemed at checkout. Since the net error is in my favour, I'm just going to leave it well enough alone, and not draw their attention to it.