It'll not be alright on the night.
Things got off to a bad start earlier with me setting the wrong angle on the right hand flash which resulted in a halo around the drop....
..... I no sooner got that sorted then the drop collisions started to go to hell. Spent what seemed like ages trying to get a result. No luck. That was it. Got the kit emptied and cleaned then stowed away. I'm going to impose a stoppage on the drops for a few days and give things a rest. Will be able to return to the task with a clear head (maybe!).