I wonder if the 4.4 V8 turbo engines are available still...? Huge power and probably too much for the Aero anyway.
Also don't forget that one or two clever people managed to get the V10 into Aeros, so a straight 6 is probably not much longer than that.
I doubt a 4 pot would do the trick aurally even if it had the power, and would certainly be a step too far in the short term even if we all end up with 3 cylinder turbos in a decade or so with or without battery power.
