Even that wouldn't work because as you pointed out, the entity running the script pays the gas, and that entity can not in every case have its gas balance in the partition that validates the script.
All the balances would have to be local to the partition and not shared - effectively like a fork of ETH for each partition.
edit: I'm considering the possibility of whether an inter partition transfer of ETH would be possible if the partitions merged once during the transfer and then split apart again post transfer block.