Ugh! I looked at Options A and C on my phone.
For background, on my Samsung smart phone (using Chrome), when I view a WikiTree profile I see one column width (and I scroll through the entire first column before I get to content at the top of the second column). Project boxes and other templates normally fill the whole width of the screen.
On my phone, the option A project box does not take the full width of the screen. The space to the left is empty, which looks like dumb use of the limited screen space, particularly when the narrow width of the box has forced odd breaks in the text, as in the example of https://www.wikitree.com/wiki/Ostrander-176 , where the first three lines of the template text appear to the right of the flag:
Pieter Ostrander was
a New Netherland
Descendant 1674-
and 1776 appears by itself over on the left underneath the flag.
The Rees-Williams-5 example looks even dumber on my screen. The hyperlinked words
Anzacs
on
Wikitree
appear to the left of the project box, looking exceptionally amateurish and making me wonder how they got there. (After viewing the page on a real computer, I figured it out.)
Option B fills the whole screen width on my phone, which looks much better.
In Option C, the template spills off the right-hand side of the phone screen, so I have to scroll laterally to read a full line of text. That looks amateurish!