I'll post it here the talk about it from Sébastien Weber : if you click on grab and that the attribute live_mode_available is True then, this live kwargs will also be true and you'll be running the live mode from the plugin not from the control module (means sending the dte_signal as fast as possible)

so i don't think it's deprecated. for more information look at the documentation: https://pymodaq.cnrs.fr/en/5.0.x_dev/developer_folder/instrument_plugins.html#live-mode