I think it can be unscrambled fairly easily. Put an upper limit on the refund...say, $30,000 (it could be more or less, but that seems like a reasonable amount).
Assuming a $30,000 limit, if your refund of imputation credit is less than that, no change.
If you would otherwise get a refund of excess imputation credits greater than that, then, too bad....$30,000 is all you get.
