(22 Mar 2023, 5:23 pm)Shrek wrote I've used it several times without issue

Yep, I've used it this week when commuting and it's done the £2 singles no problem at all when checking my bank the next day and the website. 

Some drivers seem to be pushing people to do it as soon as they look to pay by card which is good for building habits. Seems to massively speed up boarding compared to all the £2 singles that have been printed in recent months, and in my experience only slightly delays people getting off.