the 3l shouldnt need to be revved as hard for the same results because of extra capacity obviously.
There are more non hybrid engines failed due to oil pump failure than RB30 harmonics. (obviously not as many about either, but enough)
as said, if it is built well, harmonics should not be an issue, especially for a 300kw motor, and up to 400kw because the revs are not (should not) be required anyway.
if the whole lot is all balanced, harmonics should not come into play. but that all depends on the budget also.
so many builders with great results as mentioned