Interesting idea if I am following the concept.
Record full precision start times with a TIMY or ASC2 into Com to File.
Bring file or email it to the finish.
Upload during or after the race and have the start times adjusted so that they reflect the true sensor>sensor time.
Then the net times should recalculate as well.
We have found that texting the hundreths or in the case of an early start the 59.012 is very effective. You then have the text log too to review if needed.
The TDC in start input mode is very tolerant of finishes as well. We have had no problems editing start times at the same instant that finishes occur.