There may already be a canny issue for this but there's so many regarding C&C that it's hard to trawl through, and many are old so I don't know what's relevant nowadays. I know that similar issues have been brought up in the past, but here's the state of play as of now.
We've had several customers turn up to our shops, ready to collect their items because the order confirmation e-mail shows a message of "your order will be ready for collection in [x] days" - with [x] being the shortest lead time of the order's items.
This ends up with customers being angry as they've made the trip to the shop, only to partially collect their items and having to make another trip later. We've had to offer some items as gestures of goodwill, leading to several small losses.
I raised this as an issue to support but was told this was working as designed (!!!) which seems incorrect to me. I was also told that the basket page clearly shows the lead times, but at this point, it's in regards to delivery because C&C isn't actually "selected" when you go through the C&C interface on the product page and select 'add to basket' - it's during checkout
The checkout does show the collection times but then the confirmation e-mail contradicts this....and I think we're all pretty aware that people don't read whatever messaging we show them!