Handling "A La Carte" Plan Upgrades/Changes with CBSubs Options & Family Plans

Hi everyone,We are building a sophisticated B2B subscription model using CBSubs Options, CBSubs Family Plans, and CBSubs CB Fields. While the initial registration works, we are hitting a wall regarding how to handle mid-term changes (upgrades/downgrades) to our "A La Carte" plan.Our Current Setup:We have a single "Custom Plan" where the price is driven entirely by user selection:

• Duration & Renewal: We currently exclusively offer 1-year memberships. The plan is configured to allow renewals 30 days before expiration.
• Dynamic Categories: Users select multiple categories via checkboxes. These are mapped to a custom field
  Code:

  cb_category_access
  using CBSubs CB Fields. We use this field for custom ACL overrides to show/hide content.
• Additional Licenses (B2B): Users select a number of additional seats. This integer is pushed to custom field 
  Code:

  cb_amountofadditionallicenses
  , which powers CBSubs Family Plans to allow the buyer to manage B2B license-sharing.
• Pricing: The base plan is 0€, and all value is added via the checkboxes (fixed costs) and the seat counter (multiplicative:
  Code:

  *[value]
  ).

The Challenge: Mid-Term Option ChangesWe want users to be able to log in to "My Account" at any point during their year-long subscription and add/remove categories or seats. We are currently facing a "catch-22" with the CBSubs Options display settings:

• Scenario A: If we set "Require Options Change Renewal" to Yes, the "Change Options" button disappears from the user's active subscription view unless they are within that 30-day renewal window. This forces them to wait until the end of the year to make any changes.
• Scenario B: If we set it to No, the user can change their options mid-term, but the system does not trigger a payment for the added features. It simply updates the database/user fields, effectively giving them the extra categories/seats for free for the remainder of the term.

What we need to achieve:We need a way for the user to "upgrade" their existing subscription to the same plan ID but with new options selected. Ideally, the system should:

1. Calculate the price difference between the current selection and the new selection.
2. Apply pro-rating based on the remaining time in the current 1-year cycle.
3. Generate an invoice for the difference without creating a duplicate subscription or extending the expiration date (unless they are in the renewal window).

We plan to expand into Monthly and Quarterly options soon, so a scalable solution is vital.Our Questions:

1. Is there a specific configuration in the Pricing or Workflows tabs that allows a "Self-Upgrade" (Upgrading to the same plan with different options) to trigger a pro-rated invoice mid-term?
2. We considered "Campaign Codes" as a manual workaround for re-subscriptions, but this is not sustainable for a self-service UX.
3. Is our "All-in-one" plan approach the best way to handle an "A La Carte" model, or is there a better architectural pattern in CBSubs for this?

We would appreciate any advice or suggestions for building the custom plan / A la carte option, as it has been a big challenge.

There is currently no way to do a mid-term options change without doing a renewal or first cancelling then resubscribing. There are plans to eventually allow for a partial payment to upgrade to the new options selection, but that's not available yet. The feature to change options without a renewal simply changes the options then will apply those options at next renewal, but in the future that will be the partial payment feature.

The only way I can think of to escape this requirement is basically break your options out into a dozen different plans so they can mix and match them as they please whenever they please, but that brings a set of its own potential usability issues. Additional seats for example would need to stop being a free standing integer and instead be static amounts.