Well if you really want you can install AmigaOS3.9, atleast the part that was delivered with 3.9 that is (read everything but the Kick-ROM).
Back in the days of MorphOS 1.1 I accidently managed to boot my Peg1 into my A4000's 3.9 install when I had the 4000's HD installed to transfer data (back than there was no USB-support).
"3.9-apps" as in SW written for use with CPUs <= 68060 should really fly on the Efika both in CPU-power as in RAM available. Feel free to install IBrowse,AWeb,fxPaint etc.
Why one would want to replace Ambient with ancient, crippled and Hacked&Patched Workbench is beyond me, but even that can be done.