> A makes joke. B and C react "laugh". D replies with sub-joke. E, F, and G react "groan". Produce this little cascade every time a serious topic is brought up and someone makes an offhand joke as a lead-in to a serious topic.
iMessages/SMS is not a conversation or an email and the same rules don't apply. You don't have the recipient's attention for any longer than it takes to read the message you've sent. If you want to make a joke then make a point you need to do both in the same message.
That zoom on iPhone is a perfect Apple thing: here is a very useful feature, we will document it but never bother to publicize it, and it’s going to be buried behind a strange gesture requiring both hands (double-tap and hold with three fingers, then slide up or down!).
I can’t change the behaviors of others. And, in practice, while email isn’t really considered a conversation, messaging is. Stuff that would be no problem in a physical conversation (three people laugh) is incredibly distracting when every one of them feels compelled to note they found it funny.
iMessages/SMS is not a conversation or an email and the same rules don't apply. You don't have the recipient's attention for any longer than it takes to read the message you've sent. If you want to make a joke then make a point you need to do both in the same message.
You should look at how to zoom on your iPhone - https://support.apple.com/en-gb/guide/iphone/iph3e2e367e/ios