When a job is running out of KP3R, the job fails on the amount of KP3R to send.
For example the job seems to be calculating it should reward 0.2 KP3R, but when there is only 0.1832 KP3R available, it fails on this.
I would suggest it would just send the remainder 0.1832 so that the job doesn’t have credits left (and becomes inactive?)
Like this the last worker is rewarded with the remainder, which might not be sufficient to cover gas costs but it’s better than having your TX reverting with an ‘out of gas’ error.
Example; https://etherscan.io/tx/0xcdf514f6ba9b1163c7b246718f8b220072f1dc087b6bdc8fb82724ca3c4dc485