Ill give 3 maybe 4 instructions at one time to a native English speaker; BAW, QFA, RBA, THM etc.
2 maybe 3 to established European airlines - TRA, KLM, DLH, BER, RYR, EZY
Never more than 2 at a time to AFR or AZA.
One at a time to Far East carriers; JAL, ANA, CES etc, unless the pilot sounds particularly switched on.
And im sorry to say it, never more than 1 at a time to an American pilot
