Amazing change!
Kind of odd that the system might charge multiple cards if they’re within 7 inches of the reader. Seems like as soon as it registers 1 payment it should freeze for 3-5s before allowing another one.
I think the concern is that the reader might pick up a different payment form than the one you intend on using if there are multiple in close proximity. I highly doubt it will charge multiple times, as the sort of interlock you are describing is pretty standard NFC stuff. Using the same form of payment as you make transfers is needed to make sure you aren’t charged extra.
For myself, I use the commuter rail and a monthly bus/subway pass, so this isn’t terribly helpful. I haven’t really kept up with this plan though, are they planning on including monthly passes in this in the future? Some transit systems let you put a pass into a mobile wallet and scan from that, so the tech is there.
Looks like it’s basically just a tap-to-pay kiosk that you can use as you walk through the the turnstile - is that right? If so: Not sure why they didn’t go the way Clipper/DCMetro/Suica/etc did and actually integrate a virtual card into the various wallet apps. Those tend to work fantastically, in my experience.