Hey that makes perfect sense now, thanks.
I will streamline the send rates and see where I can get to.
I had 58 sensors over 5 devices sending every 10 secs 
Massive lumps of those were sent too often - I expect (hope) they never will change state, but when they do the 10 second timer would delay things (Which could be bad)
It might be worth encouraging a more proactive approach to this issue with some worked examples
maybe mentioning in the documentation some common sense approaches to ‘appropriate’ intervals - for example all the documentation is in relation to putting the virtualwrites inside a timer, in the real world virtualwrites could be tied to state changes, and thus only sent when absolutely needed, a state change could be far less infrequent in comparison to sending unchanged data every 10 seconds.
A fire sensor needs to be immediate and thus state activated, but temperature for example could be sent regularly on a timer - no need to send it 60 times a minute though, every 5 minutes or even even 6 hours could be enough for many applications.
I think with the examples all being timers it could lead newbies and non tech users down a inefficient route, not to mention 6 months ago I didn’t even understand how to use a timer
Sorry to ramble, but as a non tech user I think I may have some useful points to add - basically the parts I struggled with over the past 6 months.
Cheers for you help 
Just found this and thought it was applicable -
Clearest explanations I have found so far