On KT/PW differences in element's positioning. At least KT 5.3.2.1 (and, I assume, PW with equally recent firmware) provides
Pillow.dpi global variable in
javascripts/pillow.js script included in most (all?) Pillow HTML pages. Absence of this variable could point to device definitely being KT (but I'm not sure).
This variable, not suprisingly, contains DPI value. First part of
this article explains connection between points ("pt" value in CSS), pixels and DPI.
With using of this information, concrete margin values could be computed dynamically. BTW, KT has 167 DPI, PW has 212 DPI.