To be sure, i reinstall the plugin and i had:
CB File Field
CB File Field plugin 1.4: A CB 1.3 field-types plugin to add a file field type to available cb field types.

The issue is remain as before, hidden field still required

i just do another test with new registration.

At the new registration there is not problem, field is hidden and nothing is required for this (hidden) field.

After first login, system forced to update the profile with required fields (hidden).

(Progress field is used at the profile, but the specific field is unselected)

The below will protect a field based off the profile owners own subscriptions.

A. Field availability by Owner's Subscriptions: Yes, Detailed
Owner Plans controlling field available in profile: Your Plan
Still Available for Profile Owner himself: No
Owner Plans controlling field editable (none means not controlled): Your Plan
Still Available for Moderators: Yes
Still Editable for Moderators: Yes

Ensure you're always testing with a standard Registered user as with the above I've configured it to always be available for administrators.

In base of Krileon's post, i have do the same configuration.

A. Field availability by Owner's Subscriptions: Yes, Detailed

Owner Plans controlling field available in profile: Your Plan

Here i choose the plan where field must be appear and required.

Still Available for Profile Owner himself: No

Owner Plans controlling field editable (none means not controlled): Your Plan

Here i choose the plan where field must be appear and required.

Still Available for Moderators: Yes
Still Editable for Moderators: Yes

Also, i test all plugins for the last updates, but its fresh installation as i'm working on my test site of the same server (Licence of CB_Subs)