I use Audacity regularly. Thanks for the reminder on envelope shaping.
What I haven't resolved is transferring what amounts to key frames or in/out points from Shotcut along with the audio track(s). And sometimes it's just "gotta see it as I go".
For example, in my stock intro clip for my Alps videos, I backed into finding that the cut from the first title to the second title just happened to drop on the first beat in a measure. Armed with that, I timed the subsequent cuts for the subsequent first beats. Call it serendipity. Anyway, the result is a set of titles with a bit of punch to it.
If I'm working in Audacity, I may get the audio sounding good but not quite reflecting with what's on the screen. Which is why I suggested the sound ramp filter. Change - play back - change - play back... until it looks and sounds right.