i use this technique to do post compilation things ( ie after jdt
compilation ), and its works well when i create manually my update site
( or when i manually creates features, IE export as features ).
PDE generates ant-scripts that in turn call PDE functionality. Buckminster's mechanism doesn't involve such generation,
instead we describe the build in terms of CSPEC's and call PDE's functions using actions. If you want to customize a
Buckminster build (post compilation hooks, etc.) then you must modify the CSPEC that defines the build model. You do
that by adding a cspex where you typically rename the original action and then create a new action with the old name
that is dependent o the old.