AP Invoice in Foreign Currency On Job


We buy a lot of stuff Purchase Direct to a job. Many of our purchases are foreign currency. We are having issues where the invoice does not come for some time (sometimes months) after the job has finished.
As far as I can tell, the job needs to stay open until the invoice is entered as there is almost always an ADJ-PUR transaction which goes to the job. If the job is shipped before the AP Invoice (Which it almost always is), this value just goes to the variance account.
This ADJ-PUR is generally only a few cents and it is because of any currency exchange that has happened since the PO was Receipted and the invoice is entered.
We won’t want to have to leave the job open just to have these few cents added to the job and then posted to variance!
Is there any other option…?