Yes, I've also thought of high pass/low pass filtering into and out of ASL. Ideally, I'd use a chain that looks something like this:

DMR > hpf/lpf > limiter > AB > ASL

Throw an expander after the hpf/lpf when going the other way, and maybe not use a limiter.

Some of these digital radios are just unnecessarily hot (Radioddity GD77S, for example,) and I'd like to tame that on the way in to ASL without just attenuating the entire signal, since levels will be everywhere.