Then don’t use normal maps. They increase ram usage. But I’m pretty sure you do, because materials without normal maps don’t look as good. New hardware aren’t being built for 4K gaming only, but rather for pushing graphical details.
The matter of fact is, dynamic G.I is the new standard, almost every other engine already has a form of dynamic G.I. Give it just a little more time and the absence of dynamic G.I in UE4 is going to show as apparent as “the material with and without normal map”.