OpenVPN doesn't know "site-to-site" vs "remote access". It just knows point-to-point and point-to-multipoint ("server/client" mode). pfSense masks all that in terms users are more familiar with by changing the GUI options to make it more like what our users have expected and requested over time.
Under the hood, a Remote Access VPN and Site-to-Site SSL/TLS VPN (with a tunnel network larger than a /30) operate in the same way using the client/server mode of OpenVPN.
Exit notify only makes sense for UDP, since TCP will already know when a connection closes.
If you re-read the OpenVPN man page with all that in mind, it makes more sense.