Cant help you there as I have only ever done it one way, I immagine that P Bowen on the other topic is putting the smaller section inside a larger section and sliding it down to the end to get the double reinforcement. It does mean that you dont have to buy anything else.
Here is a poor quality pic of a st connection with no goose neck.
I don like goose necks and prefer an unger angle joint
,and have lately been pleased with cutting off the broom holder completely and fitting this onto the end of a strong glass fibre section which then slides over your F16 section., which allows the brush angle to be infinetely changed.
For this assume the unger elbow is not in the pic and the unger handle push fits on the glass fibre section, this allows you to instantly remove the brush and use it in your hand. Or change the angle for cills.