What about running balanced high end external preamps / gear through those onboard preamps? I do hate the idea, but does it really make a noticeable sound difference vs a line level input like on an RME? Onboard preamps seem almost unavoidable on multi-channel converters these days!

Yes, I know that I have the option to use the insert on channel 1+ 2 with an unbalanced connection to bypass the pres, but what about the others?