Like I answered last year, profileFields is not an attribute available on Lock, and therefore not a workaround for this common use case.
Since then, was added the connectionScopes property, which could fit the idea if it was possible to set it to r_liteprofile instead of the default r_basicprofile (the problem being currentShare being returned by the r_basic_profile scope).
But as far as I know, this is only available on LinkedIn API v2, and we are currently on v1.
I opened a topic about this.