OWS Signal 4.6.0 declines to use microG Services Core 0.2.4-92-g3669bab, says version is too low

I'm having issues using Signal with microG.
Problems match those described in https://github.com/WhisperSystems/Signal-Android/issues/6392

moxie0 comments on the issue there:

[the problems started when OWS updated the version of GMS used in Signal, so] I assume microG isn't properly reporting that it is API compatible with the updated version.

That hypothesis is supported on my device (i9300, Replicant 6.0) by the Signal debug log, which includes:

3593  3610 W GcmRefreshJob: Reregistering GCM...
3593  3610 W GooglePlayServicesUtil: Google Play services out of date.  Requires 9683000 but found 9258259

MicroG in itself appears to install well. Installed via F-Droid. The self tests are OK.

From a user perspective it seems like the easiest way out of this problem would be if microG reported a higher version. While looking for a solution I saw some comments about other programs complaining about outdated services as well.
Could you make this change? Could I myself work around the issue somehow?

Start by tracing the GooglePlayServicesUtil version check shown in the debug log and compare how microG reports its installed version with Signal's required version. Confirm the compatibility behavior around GCM re-registration and verify that the out-of-date warning no longer occurs for the reported microG version.