For me, being comfortable completely flatbasing was one of the breakthrough moments in my progression. So keep practicing the microcarves and just get comfortably crossing through flat. Once you can do that, it will help limit the speed in itself, but you'll find you no longer need to go completely heal/toe edge to scrub once you get too fast. Once you get comfortable and relax, you'll find you have the confidence and control to stay flat longer (if you want to) and even the whole run in you feel like it. You'll be able to scrub speed by gently rocking back into micro carves if you need to. I wasn't kidding on the tail pressing either! There's almost no way you can catch an edge in a tailpress
Perhaps the hybrid camber board helps but I've never really found a need to always keep slightly on one edge like people have old me you should, it feels more natural flat to me.