Are there techniques to minimize user profile (re)definition?
Yes. These include the use of group users and role based users.
Using group users will not impact how many user profiles need to be defined, but it significantly impacts their ongoing maintenance. It is easier to maintain a single user group than a set of individual users. Note that the Framework allows a user to be a member of multiple groups, which is different to IBM i. You can use Framework user groups without having to use IBM i group profiles.
A role based user is where the real user is mapped to a much smaller set of Framework role based users.
For example real users Fred, Mary and Bill might all map to the single role based Framework user profile ACC_CLERK.