I don't exactly follow your question sorry.
Idk why butcher mod has pallet stuff lol but what does it do in that mod exactly
here is the code from the butcher mod
<append xpath="/blocks/block[contains(@name, 'palletWhiteBagsBase')]">
<property name="CanPickup" value="true" />
</append>
<recipe name="resourceConcreteMix" count="2500" craft_time="300" craft_area="tablesaw">
<ingredient name="palletWhiteBagsBase" count="1"/>
</recipe>
and here is your code
<append xpath="/blockplaceholders">
<placeholder name="palletWhiteBagsBase">
<block name="palletWhiteBagsBaseFull" prob=".66"/>
<block name="palletWhiteBagsBaseEmpty" prob=".33"/>
</placeholder>
</append>
<block name="palletWhiteBagsBaseEmpty">
<property name="Extends" value="palletWhiteBagsBase"/>
</block>
so the palletWhiteBagsBase that is used in the tablesaw in the butcher mod know is nowhen as palletWhiteBagsBaseEmpty.
im going to try having your mod load first and change palletWhiteBagsBase too palletWhiteBagsBaseEmpty in the butcher mod recipes and see if that works.
-----Up Date-----
I got them to work too gather. I had the pallet and the Home Brewery mod load first and I changed palletWhiteBags to palletWhiteBagsEmpty in the ButcherMod that goes for all pallets and wineBarrel.