@beelee
We have to issue a warning when using this method, so here goes!
Warning! endTurnNoPU only stop the PUs that are gathered from territories! Objectives will still be paid!
Take PoS2 which has a first step of "Tech" which can be turned off in the 'Game Options'.
Adding endTurnNoPU as the first step:
<!-- endTurnNoPU add to center map on player if "Tech Development" is unchecked -->
<!-- Italians Game Sequence -->
<step name="italianNoPUEndTurn" delegate="endTurnNoPU" player="Italians"/>
<step name="italianTech" delegate="tech" player="Italians"/>
<step name="italianPurchase" delegate="purchase" player="Italians"/>
<step name="italianPolitics" delegate="politics" player="Italians"/>
<step name="italianCombatMove" delegate="move" player="Italians"/>
<step name="italianBattle" delegate="battle" player="Italians"/>
<step name="italianNonCombatMove" delegate="move" player="Italians" display="Non Combat Move"/>
<step name="italianPlace" delegate="place" player="Italians"/>
<step name="italianTechActivation" delegate="tech_activation" player="Italians"/>
<step name="italianEndTurn" delegate="endTurn" player="Italians"/>
Now the Russian player you get this:

Please note that the Russian will receive no message, but because of the objective they will receive the 4 PUs.
This can be handled with a "switch":
<!-- This condition controls when National Objective happen with a switch -->
<!-- and should be added to all objectiveAttachment -->
<attachment name="conditionAttachmentNationalObjectiveSwitch" attachTo="Germans" javaClass="RulesAttachment" type="player">
<option name="switch" value="true"/>
</attachment>
<!-- German Objectives -->
<attachment name="objectiveAttachmentGermans1_EasternEurope" attachTo="Germans" javaClass="games.strategy.triplea.attachments.RulesAttachment" type="player">
<option name="conditions" value="conditionAttachmentNationalObjectiveSwitch"/>
<option name="objectiveValue" value="4"/>
<option name="alliedOwnershipTerritories" value="East Balkans:Eastern Europe:Ukraine S.S.R.:Belorussia:West Russia:Norway:Karelia S.S.R.:Archangel:Caucus" count="7"/>
</attachment>
The condition should be added to every objectiveAttachment. Then 2 triggers control the "switch".
<!-- PoS2 used conditionAttachment_Americans_Aid_UK as an "AlwaysTrue" condition -->
<!-- While this is ok, this condition should be checking if Americans have -->
<!-- enough PUs to give to the British -->
<!-- This trigger changes NationalObjectiveSwitch to false -->
<attachment name="triggerAttachmentNationalObjectiveFalse" attachTo="Germans" javaClass="TriggerAttachment" type="player">
<option name="conditions" value="conditionAttachment_Americans_Aid_UK"/>
<option name="players" value="Germans"/>
<option name="playerAttachmentName" value="RulesAttachment" count="conditionAttachmentNationalObjectiveSwitch"/>
<option name="playerProperty" value="switch" count="false"/>
<option name="when" value="before:italianNoPUEndTurn"/>
<option name="when" value="before:russianNoPUEndTurn"/>
<option name="when" value="before:germanNoPUEndTurn"/>
<option name="when" value="before:britishNoPUEndTurn"/>
<option name="when" value="before:japaneseNoPUEndTurn"/>
<option name="when" value="before:americanNoPUEndTurn"/>
</attachment>
<!-- This trigger changes NationalObjectiveSwitch to true -->
<attachment name="triggerAttachmentNationalObjectiveTrue" attachTo="Germans" javaClass="TriggerAttachment" type="player">
<option name="conditions" value="conditionAttachment_Americans_Aid_UK"/>
<option name="players" value="Germans"/>
<option name="playerAttachmentName" value="RulesAttachment" count="conditionAttachmentNationalObjectiveSwitch"/>
<option name="playerProperty" value="switch" count="true"/>
<option name="when" value="after:italianNoPUEndTurn"/>
<option name="when" value="after:russianNoPUEndTurn"/>
<option name="when" value="after:germanNoPUEndTurn"/>
<option name="when" value="after:britishNoPUEndTurn"/>
<option name="when" value="after:japaneseNoPUEndTurn"/>
<option name="when" value="after:americanNoPUEndTurn"/>
</attachment>
So now you have this for the Russian player:

Even though the Russian objective is true, there is no payment line. The first line is switching off the objective, the second, highlighted line, is the NoPU not giving any PUs for territories. The last line, which happens after the NoPU turns the objectives back on.
There are other items to worry about, such as territoryAttachment "resources" and with unitAttachment "createsResourcesList" and "createsUnitsList". These are also done during an endTurn/endTurnNoPU. These would need to be reset with trigger that use "-reset-", and another trigger to return them back to their original values.
Any active step can be used but each come with their own set of "problems", but I find that endTurn/endTurnNoPU will always happen and can be used in different ways.
Enclosed is a modified PoS2 file.
modified_PoS2.zip
As always Have Fun!!
Cheers...
P.S Credit needs to be given to @TheDog and GCD '41, which I blatantly ripped off. Check out the map and xml, there's alot of good stuff there.
All hail @TheDog 




Cheers...