The contribution that was removed before the due date of the tax year return, means all you report is the earnings. That won't "keep changing" MAGI, because it also should have been removed, and it's the only thing reportable. Earnings on excess are reported for the tax year of the contributions that were in the account. If the excess keeps changing because the taxpayer would be allowed a partial contribution, you still have only the actual amount removed to deal with.

If excess contributions and earnings were in an account year after year, they are subject to the 6% excess penalty, until removed. That won't increase income until it is removed.