a pyroclastic cloud

Hello everybody,
I need to make a pyroclastic cloud starting from your Volcano preset, but the dynamics of the whole preset are too fast for my needs.
let me explain better, a kilometer high cloud is extremely slow in its evolution and upward gravity movement, would you help me understand what parameters I can change to obtain a slow but equally beautiful volume?
I tried with various combinations, but without being able to drastically slow down my cloud.
thank you

One way to slow down the speed of the simulation is to click on the ‘simulation’ node and then increase the value in the ‘Timestep’ field.