Looks like you got plenty of input on this....Im with ppl that are saying keep the RH below 50% in your flower area or have more circulation...Maybe have a fan that blows across plants...
To avoid this myself theres a tiny trick where on those big top colas if your worried about rot?....For 1 always watch for "Dying-off"...
This is when the upper Fan leaves die-off and then would naturally fall off....Where that fan leaf dies is also where the Rot will start as its a death of the node point as this is the latest stage of flower..
So if you see a very yellow leaf and it looks weak late Bloom...Remove it,..,.
Also - Old Skewl huge Cola trick -Pull the Buds AWAY from the Stalk before Rot ensues.....ez..... power to it
Far as what to do with rotted bud...thats your call...
Spicoli/FOE20
ps: on Humidity ...these guys are very correct by saying keep RH under 50%....Look at it like this...
At 51% RH theres still a tiny bit of residual RH to feed mold and rot(this is bad)...at 49% RH the room is Pulling a bit moisture from the area and plants(this is good)...This is the Logic behind it...gl