Tremolo inconsistencies

Here is an example of a quick piece I threw together to demonstrate some issues with tremolos, and am asking that in the future we have stronger tools to handle these.

In measure 1, the beam height is different between Beats 1 & 2, and 3 & 4. The tremolos are placed in the same spots. But Dorico draws these differently, and I cannot seem to find why in any preferences. I prefer the look of the second half of the measure. The first isn’t bad, but the 2nd seems more “space saving” to me, with the shorter stem lengths.

Same in the second measure. the first half is the default. The tremolos sit above the staff, but in the measure with 16ths, the sit on the top line. The default in measure 2 looks ok, but I think the second half in measure 2 looks better.

I can come up with other examples too of the Z on stem. sometimes it sits nicely, sometimes it’s hanging off the top of the stem for no apparent reason.