Yep, no credit card reader required. But you do have to have an automated toll-free number for people to use to make payment. (SMS for payment is an option as well.) So the app can't be the only method.
No current Tesla Supercharger infrastructure qualifies for funding. It required that every funded port be capable of providing 150kW anytime a vehicle asks for it. (Power sharing is only allowed above 150kW.) V3 Superchargers generally have ~90kW available per port when all are in use. To meet the requirement Tesla would have to get a larger grid connection/transformer and double the number of charging cabinets. (Only 2 stalls per cabinet.)
They could pull "tricks" like having only 4 NEVI funded ports per site, but that would cripple the other Supercharger stalls at the site. (For example, a typical 12 stall V3 site has a ~1000kW transformer, if you dedicated 600kW of that for 4 NEVI funded stalls that would only leave 400kW for the other 8 stalls, or 50kW per stall if they were all in use at the same time.)
What they could do is up the grid feed/transformer to 1500kW and add an additional V3 cabinet, to make 4 NEVI stalls, at 150kW minimum, and use the remaining 900kW for the 8 NACS only stalls. But I am sure that non-Tesla drivers would be very upset if they arrive, and the 4 NEVI/CCS stalls were in use by Tesla vehicles, and they couldn't use any of the open 8 NACS stalls. (I guess Telsa could put CCS connectors on all of them, even if they weren't funded by NEVI so wouldn't require the minimum 150kW output.)
It will be interesting to see how this plays out.