If you see “balls” early on in flower they are likely from stress. I have seen them from pruning in flower and nutrient stress. They tend to form single balls right off the node at the stem.
These likely contain viable pollen. But can be picked off and if the stress is removed they may not come back.
Late “nanners” can grow single or in bunches. These are actually the inside parts of the male flower. The balls are unopened male flowers. They need to open to release pollen so if in ball form they are still safe.
But nanners if seen can already pollinate. They can be viable, weak or sterile. They can be hidden in the bud some and that’s when you get a few seeds but never saw male parts.
I have strains that show single nanners about week 8-9 but I like to go 10-11 for best potency. Usually no seeds result. But sometimes a few are found.
The late nanners frequently are found in upper buds. They drop pollen to the lowers where we find the seeds.
I always feel a few can be managed but if a plant has a full breakout and it continues I always chop it before it cross pollenates my multi stage perpetual garden.