Thank you, I have managed to gather sufficient information relating to how this is behaving at the moment (Not all from the provided links however I will accept that answer, Thank you @Anonymous )
As a courtesy to the rest, please find some additional information I discovered through testing.
The limit of the Queue into which these requests go seems to not be limited by number of requests, but seemingly total size of all requests in the Q (I.e. the bigger the reports you send, the lower the number of individual requests that can go into the Q before your requests will starting being rejected)
There is info about reports requests over 250mb being entirely rejected all together (perhaps a correlation to the point above)
Exports can progress across reports simulataneously, rather than going one at a time from 0-100%, could potetially cause earlier requests to take longer than they should and cause user frustration, my preference is first in first out but regardless, your own Q as a middle man ensuring they are passed one by one requiring the previous requests completion before pushing the next is easily do able.
I am not certain about higher SKU's regarding Azure capacities but from embedded SKU A1 to SKU A2, the maximum size of the Q for these requests does not increase. (again I believe there is a correlation between that Queue size and the single report 250 mb size limit for requests.)
I hope people find this info useful.
Kind Regards,
