I know that wasting a coil is a tough call sometimes...but you very well could just have a dud, or some hotspots causing some issues... even in the replacement .4 coil...
I remember picking up a pack of aspire coils a few years ago, and literally only one in the pack was "right" the others were harsh, and created much the same experience you described. Max VG juices should be smoother, and once you have more experience a bad coil will be super easy to spot (probably will remind you of today, lol)
I get what you are saying about "satisfying" Even some MTL vapers need that big vapor production to feel "filled up" or to get their "hit size" consistent with their smoking expectations. This is why many folks aren't successful with cig-a-likes, and the more inexpensive MTL starter kits. I know mine only lasted a couple of days when I bought my first vape (Blu) and I was back on stinkies for a few months until a trusted friend expressed his disappointment and gifted me his MPV with a no name RDA on top... one hit and I was changed forever... all because I could get the volume of vape (not necessarily "big clouds") to satisfy.
Excited you were able to leverage the community to help troubleshoot, and get some food for thought!