when you search by part number at the realoem.com parts catalog, it shows that oil pump being used on e28 (e and td), e30 (e and i), and e34 (525i)
http://www.realoem.com/bmw/partxref.do?part=11411720898
and I can’t find any reference to any other pump being used on e30’s (other than euro td’s)
so, it may only have internet-myth benefits but if it is better then it should be legal since it is listed for US e30’s.
just found that there is a second oil pump listed for 524td’s - 11411275093 Maybe that is the higher volume one. It was only used on td’s
bruce