[M] Refine: Variance Warnings

This ticket is to track refinement time needed for getting variance warnings ready to implement in #255

AC:
- go over designs in #255 with business area and make any changes
- break down #255 if needed

Notes:
- Refinement meeting took place Jan 30th with Sally and Nicole to go over designs and implementation ticket. Details have been captured in AC of #255 - which is now unblocked and ready to tackle.

Start with issue #255, where the variance-warning designs and implementation acceptance criteria are recorded. Review those designs with the business area, update the requirements, and split the implementation work if needed; the refinement is done when #255 is unblocked and ready to implement.

Written by the indexing model from the issue text.