I've used it a couple of times and it was fine. Just remember that you have to touch out when leaving (easy to forget to do this!)
Indeed, this is one of my other gripes about the discontinuation of One Day Travelcards from the “Get Me There” app. It’s now (since June) either paper tickets from the TVM or contactless as means of payment.
I’ve no issue with contactless per se and have used it for years on LU, however when you’ve become accustomed for years to just walking off an unbarriered platform as you do on Metrolink, it’s very easy to forget, particularly if you don’t travel very frequently.