If you really want to contact Evinrude Engineering, try sending a letter to the Sturtevant, WI address saying ATTN: Evinrude Engineering Dept., Chief Engineer
With a bit of sluething and Googling, you could probably find the gentlemen's name even.
The deal with the bigger BRP v 6 engines is that after 275 hp the case bangs its self up. This why BRP cannot compete with the Mercury. This was shown to me by A person that worked for OMC as A racing tech consultant. This person showed me the differences between the OMC engine, & the Mercury engine. (btw he raced A Mercury 200 weekends while working at OMC)