And im sorry to say it, never more than 1 at a time to an American pilot
Not sure where this blind prejudice comes from. The majority of the world's aviation takes place in the USA and their safety record is as good as the best in gold plated Europe.
More than likely the American pilot cannot understand a "regional UK" accent - I find some accents impenetrable and that's before one gets to the dreadful language they call "English" spoken by many ATCOs in the more southern parts of Europe.
I've read some recommendation somewhere about limiting the # of items to 3 but don't recall whether this was CAA (UK airways ATC) procedures, or ICAO.
One needs to develop a shorthand for writing down stuff, and have a pencil handy before making a transmission.