Your assumption is mistaken.
Any amount of capital loss can be carried forward.
The $3000 limit is the amount of capital loss in excess of any capital gains that can be used to offset ordinary income.
So if you had gains of $5,000, losses of $10,000, you could offset $3K of ordinary income in year N and would have a $2K carryover to year N+1. If you had gains of $5K and losses of $20K, you could offset $3K of ordinary income in year N and would have a $12K carryover to year N+1.
In general, Taxact seems to get most mainstream scenarios correct.