I have the same issue as you, it will affect anyone running multi-lap regattas particularly where there is a combined start finish line.
Currently after the first pass through the start finish line no further race analysis of tacks or gybes is possible. I am guessing that maximum speeds and other data will also be restricted to the first lap performance only.
I believe the solution is an enhancement which enables the finish time to be set when adding the finish line or a combined start/finish line. i.e similar to setting the start.
My workaround is to split the combined start/finish line used for the actual race and create “fake” RaceQs finish line across the beach, well away from the actual finish. Boats returning to shore after racing will cross this line and trigger the finish. This makes analysis of the final leg a bit pointless which is a shame as its the finish! but at least you can analyse tacks and gybes for all the preceding laps and see the Ts and Js in the timeline.
There are plenty of requests for “nice to have’s” but there can be few things as important in a regatta as getting the start and finish in the correct place so I hope this requirement can be catered for in some way.