Safeplaces do not supersede the CRA, they merely may facilitate the goods into a customer's possession. If anything goes awry, that argument is once again between the retailer and courier.
I'm sure I've read it somewhere, will try and dig it out.
I've certainly used that specific part of the CRA to great success, even recently with a friend who had a phone delivery from Google that DPD claimed to leave outside his door.
Safeplaces do not supersede the CRA, they merely may facilitate the goods into a customer's possession. If anything goes awry, that argument is once again between the retailer and courier.