The externally provided bright object masks (via the butler type "brightObjectMask") can be applied in AssembleCoaddTask with a config config.assembleCoadd.doMaskBrightObjects=True to mask bright stars and other troublesome objects. While the default doMaskBrightObjects has been True in obs_subaru, only a warning message is given when the bright object masks are not available in the repo, like this:

(assembleCoadd.py:725)- Unable to read brightObjectMask for DataId(...): No locations for get: datasetType:brightObjectMask dataId:DataId(...)

It would be better if users had to set a configuration to turn them off, with a hard error if they can't be found. Otherwise it's far too easy to run without them when you don't want to.