Personal experience of seeing it's application over 12 years. You've had some shockers and wrong application over recent years for example a person saying a police horse is 'gay'.
Harvey vs DPP 2011 is a good example of how a few F bombs might get you arrested. The case determined that the word **** isn't so commonly used that it's no longer offensive.
Various examples from Inews, heckler arrested in Scotland for shouting at Prince Andrew, a protestor was also arrested during Edinburgh's royal events for holding an anti-monarchy sign, while in London a video emerged of a protestor being escorted away from the gates of Parliament by a group of London Metropolitan Police Service officers as he brandished
a sign that read "Not my King".
In Oxford, a man was arrested on Sunday on suspicion of behaviour likely to cause harassment, alarm or distress under section 5 of the Public Order Act 1986 after shouting "Who elected him?" about King Charles III. He was later de-arrested.