Use of Acts::UnitConstants in DD4hep plugins

[wdconinc]

In our (pre-19.1) DD4hep plugins, we use constructs such as the following:

    Acts::ActsExtension* beamPipeExtension = new Acts::ActsExtension();
    beamPipeExtension->addType("beampipe", "layer");
    beamPipeExtension->addValue(0.001 * Acts::UnitConstants::mm, "r_min", "envelope");
    beamPipeExtension->addValue(0.001 * Acts::UnitConstants::mm, "r_max", "envelope");
    beamPipeExtension->addValue(0.001 * Acts::UnitConstants::mm, "z_min", "envelope");
    beamPipeExtension->addValue(0.001 * Acts::UnitConstants::mm, "z_max", "envelope");
    central_det.addExtension<Acts::ActsExtension>(beamPipeExtension);

This seems to become impossible with the separate plugin (I admit this is a bit of a trivial example, since Acts::UnitConstants::mm == 1). Is there a plan to support units in this separated plugin?

[wdconinc]

The reason for these particular addValue statements is a different story. They originate in exactly overlapping sensor and envelope surfaces that were an issue probably around about the Acts 8.03 days...