Question
There was a seed investment in my startup. The seed investor tends to run the idea on third parties and get an experience in pitching/negotiating while searching for an angel investment. Even if the outcome is negative the experience might give us feedback on the idea itself. It's a first startup for both of us. The reason not to do it - distraction of valuable time on preparation with lower probability to get financing and falling behind the schedule for round A.
Answer
Do a bridge round only if you need the funds for critical operations. If you can postpone it or manage till A then avoid it, so that you get best valuation and retain more equity.