Directly voting for Trump will have the opposite effect. It will show democrats they should be more like Republicans because everyone was voting for Trump.

By putting the votes in a visible place (a third party), the democrats will observe they are missing out on a lot of votes which are directly cast for a left wing agenda. And instead of Dick Cheney they might show up with a left winger in their next campaign to win over those third party voters.

Donald Trump will not be a benefit in the short term. But rewarding democrats for only appealing to right wing voters will not be a benefit in the long term. They will shift even more to the right in 2028.