@Luke52 I have a couple of August Smart locks also, and you are entirely correct about the trouble of having the guest set up the account ahead of time (or rather, *not* setting up the account ahead of time).
I also use the keypad, and just have to manually set the guest up with an access code, which I send to them the day before.
You are right: it sort of defeats the purpose of the automated integration.
I have heard that August is working on upgrading its software to automatically set up and send the keypad codes also, so at least that would be handled even if the guest never set up an account.
I am glad you have a found a solution that works better for you!
One of these days, hopefully someone will design the *actual* perfect AirBnB smart lock.