Hi,
Assuming that portability is important. I wonder if a stiff bungee cord attached to the tripod head and an ‘auger earth anchor’ (see GOOGLE) under the centre of tripod might hold things stable enough for your purpose? A bag full of sand (much beloved by eclipse chasers) might swing in the wind and be more of a hinderence than a help. But an auger would put the whole thing in tension, with the whole planet on the far end!
Roy