Friendly banter is really not difficult.

Seriously. Being non-aggressive with the all-chat is not all that hard. For example if their adc keeps kyting you and flashes away the second you leave bush, you don't have to offend them or call them a coward. You could just say something like "come here and feed me plz". Not aggressive, not insulting, not gonna get you chatrestricted/banned. The worst thing that can happen here is the enemy doesnt humor it and just says "no".

Or competitive banter. If you steal dragon or baron you dont need to screech "noobs" in all chat. A simple "ty for leash" does the job with 0 toxicity contented.

Harmless Bantering is possible and actually decently easy, even if extremely restricted.