I actually don’t think it is a deal breaker. How many 300+mi road trips does a person take? So what if it takes longer a few days out of the year?
And you can always prioritize fast charging when shopping EVs, if that’s important. We knew full well we weren’t getting the fastest charging EV when we bought ours. But, like I said, it was fine on our big trip, and really we didn’t stop more often than we usually do, even if our stops were a bit linger, and it didn’t have a negative impact.
App wise I recommend just using the progressive web app (install website as app). It works very well, and you always get the latest updates.
For the server, find one that targets one of your interests.