I too prefer the first.
I only process using StarTools and am not familiar with a "morphological" transform in that process. Please inform what the equivalent is in ST!
I tend to mess around in ST until things look better and although I track my process as yet I have been unable to find a work flow that works every time.
Sometimes auto dev works well, sometimes manual dev, sometimes depends on the subject and/or sky conditions.
Even though I use the same DSLR with same settings and exposures it really depends on moon/no moon, hot night/cold night, humidity, wind, seeing, LP and whether there is a letter A in the month.
Sometimes I try some really unorthodox paths just to see but usually the results end up the same no matter how I approach it.
I find I have to custom tweak just about every stack differently. Not complaining. In fact I enjoy the artistry involved.
Like your examples I can generate less large fuzzy stars or more fuzzy stars but don't ask me if there is any logic in all this.
The end result is the way I want it through trial and error and I am very tolerant of error!