Heel and toe must be performed extremly well to be better than normal downshifting.
In FWD cars it is not so important, because it is easier to avoid blocking the front tires.
In a powerful RWD car, you usually want to tap the throttle when downshifting from 3rd to 2nd gear because you can brake quite harder if you avoid the rear lock.
Though my real advise would be to learn to drive normal, you'll quite some time until you are able to reduce gear, brake hard, keep the steering wheel pointing where you want and lifting the clutch slowlly to not lose your rear.
I needed several months until I felt confortable in almost any circumnstance, but I'm still not doing the heel and toe because this need me wearing shows while driving and I prefer going barefoot on my socks haha