In testing Station Engineers, verified that the vanilla issue causing docked Construction URVs to not be marked available was indeed causing the Engineers to do all subsequent repairs at a much slower rate because they were no longer counting these Construction URVs.

This is a tiny workaround to fix the vanilla issue with engineers not using Construction URVs that are not marked available upon docking, or that fail to dock.

It works simply by having Engineers count Construction URVs that are in usage by the ship or station in which they work, regardless of whether the drones are marked available or unavailable.

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28.Jun.2015 - v0.05 is up.

Compatibility update.  Now compatible with Linux and Mac versions.

.......
18.Feb.2015 - v0.04 is up!

Slightly changed the code resulting in slightly fatter code but much improved compatibility, better than that in v0.03.  (Thanks, Marvin Martian!)

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The mod, in its entirety, as of v0.04, is:

<?xml version="1.0" encoding="utf-8"?>
<diff>
    <add sel="/aiscript/attention/actions/do_if[@value='$repairratefactor == 0']">
        <do_if value="($repairratefactor lt 1) and ($Defensible.units.{unitcategory.welder}.count ge 1)">
            <set_value name="$repairratefactor" exact="$Defensible.units.{unitcategory.welder}.count" />
        </do_if>
    </add>
</diff>

in aiscripts\engineer.ai.xml

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Note on Compatibility:  denison10 (angel618 on Steam) recently incorporated this code into his mod, Engineer 100%, with my permission.  This effectively breaks compatibility between Engineer Drone Fix and Engineer 100%.  Please do not install both of them at the same time.

Current, but most likely unnecessary, as of X:R 3.61
Compatible with X:R 3.60

Compatible with Windows, Linux, and Mac versions of X Rebirth.