You can always finetune. If you use the install.directadmin.sh most things should be fine.
However, CSF does not react on the bruteforce monitor of DA itself, so attempts to login to the control panel.
You can create a script for that or search the forums of alternative ways. There are several topics about it.
DA bruteforce does detect bruteforces to the DA system and can block them if set in the admin configuration. But then you have the DA and the CSF blocking system, which makes it more work to lookup blocked ip's if some customer is blocked.
It just makes things a lot easier and more configurable doing it via CSF.