The 1858 Wright edition added the adverb forth here in Ether 3:9. The first two RLDS editions followed this intrusive reading, but the 1908 RLDS edition restored the original reading without the forth. The expression “to come before someone” is not too common in the text; there is only one other example, and the meaning there is metaphorical: “good and evil hath come before all men” (Alma 29:5). But there are no examples of the redundant “to come forth before someone”. For the expression “to come (forth) and stand before someone”, there are examples with and without the forth:
Note, however, that the two examples with forth deal specifically with the coming forth at the time of the resurrection and are therefore not quite the same as the other cases without the forth. The expression without the forth in Ether 3:9 is definitely correct.
Summary: Retain the earliest reading without the forth in Ether 3:9: “and never has man come before me with such exceeding faith”.