Hitting 75% or even 80% total active cannabinoids (TAC) can absolutely be done with ethanol. Single pass, no post processing. Decarb it, and it will even make a passable cart. Certainly for home use or in “dry” locations. Decarb under pressure to retain terps? - #9 by StoneD
55% is because you soaked, and used IPA which pulls more fats. You also want -50C solvent not -20C
If you can’t get ethanol, this may not be relevant: Iso vs ethonal
Edit: you will almost certainly be leaving cannabinoids behind if you’re hitting 75% TAC or above without post processing (10-15% of them in my experience). But it beats post processing imo.