I made a tech that disables some units (which were previously enabled by 'Age0{civ}' tech), e.g.
<Effect type ='Data' amount ='0.00' subtype ='Enable' relativity ='Assign'>
<Target type ='ProtoUnit'>Grenadier</Target></Effect>
The unit is disabled, but the train button is still there taking up space. So I tried removing it with:
<Effect type ='Data' amount ='-1.00' subtype ='AddTrain' unittype ='Grenadier' relativity ='Absolute'>
<Target type ='ProtoUnit'>ArtilleryDepot</Target></Effect>
...but no such luck. I even tried removing the unit's train button from the building's proto, and instead used an AddTrain at each place in techtree that it's enabled, but to no avail.
Is there a RemoveTrain effect subtype or suchlike?