Client replay doesn't update request timestamps

Steps to reproduce the problem:
  1. Save flows to a file, saved.mitm
  2. Wait a few minutes
  3. Use a command like mitmdump -n -C saved.mitm -s -w replayed.mtim to replay the saved flows.
  4. The observe the flows with mitmproxy -n -r replayed.mitm and see that the request-response time of the flows are inaccurate because it seems to be calculated using the start time of the requests in saved.mitm.
Any other comments? What have you tried so far?

If such behavior is intentional, what’s the recommended way to set the request timestamps so that they reflect the time when the requests are actually replayed rather than the previously saved timestamps?

System information

Mitmproxy: 4.0.4
Python: 3.7.0
OpenSSL: OpenSSL 1.0.2p 14 Aug 2018
Platform: Darwin-17.5.0-x86_64-i386-64bit