OK, I’m going to look at my links now as I’m pretty sure they are worn more than the OP’s
But FWIW - my first thought was it’s running too lean - when playing with carb needles and tuning, I found the needles with a wide taper at the top part made the car very sensitive to throttle inputs when cruising or at low revs.
It’s worth looking at the tune and making it a half turn richer to see if it makes a difference. But ideally you would do that with a gas analyser (friendly local MOT garage or AFR sensor).
So in summary, yes if the pistons are rising too fast you can have this issue - buy the official SU carb damper oil from Burlen or off eBay for £12 and / or have a quick play with the mix - but make sure you don’t put your carbs out of balance I.e. jets at different heights on each carb.