... just presents the login page,checks the token and places netfilter rules. Telling apart ticketed from unticketed traffic is done through Linux' netfilter.
As no proxy server is involved, jkaptive has no performance penalty, nor does it create problems with non-http traffic. Once the token is accepted, jkaptive is out of the way of any network packets completely.
For presenting the login page, jkaptive has a built-in webserver, so no additional webserver application is needed.