I've always been of the opinion splash buffs in EiRR are utterly useless as they only affect the outer rim of the splash, in most cases - which is about as useful as training the forearms of a Kenyan runner.
Unless Henschel design has been made an exception to the rule, I don't think many people will notice the splash increase much.
Checked the RGD's, Henschel only extends the outer layer of splash.
So yeah, the effect is minimal at best.