FluidNC only reports '$10' on a '$$' request

[buster3]

Machine Context

Custom build laser engraver.

Feature Description

FluidNC should work with LaserGRBL frontend. The report '$$' is not compatible with GRBL. Currently only '$10' is given. '$30' is required.

Other Approaches

implement a workaround in LaserGRBL

How I Can Help

I can implement the feature, but need a hint were the '$$' report is generated.