I have Keymaps on my M3 key (G15 keyboard) and Keyboard Repeater on M1 and Mouse Repeater on M2.

Each is a two step mapped key.
Step 1 turns the light on, and enables the Keymap.
Step 2 turns the light off, and disables the Keymap.

When I want to chat, I press M1 and M3, until the lights are off.
And chat away normally.
Takes all of 2-3 seconds.