Just a word of warning to anyone who hasn't yet installed the COROS firmware updates, released on May 10 (V 3.0408.0) and May 21 (V 3.0409.0).

My recommendation would be not to update your firmware until COROS fix an issue that was introduced in V 3.0408.0 and affects the speeds recorded when in speedsurfing mode.

The issue mainly affects the max 2s and 10s results (reporting too low) but for anyone interested, full details are available on GitHub.

logiqx.github.io/gps-details/devices/coros/smoothing/

Has this error been addressed to GP3S or Coros? Is this something they are aware of and working on?

Yes, Michael shared all the info with us, and we have notified Coros about this, in the mean time don't hesitate to report this also to Coros directly, a bit of pressure is always good ->  https://support.coros.com/hc/en-150/requests/new

Update 31 May: The COROS product team are now aware of the issue. The timeline for resolution is not known, just yet.