@Bustagate further to #8 above.

Another new sign has been placed on the A4 Great West Road (e/b, about 10m east j/o Weltje Road). I noticed this on Tuesday 14 August, but only managed to photograph it yesterday.
The x-height appears to be the same as the other temporary advance direction sign mentioned in #8 (although I haven’t confirmed this). In addition to the points already raised, it’s worth noting:
(1) The sign is positioned behind a lamp post making it almost invisible to approaching traffic. The TSM Chapter 3 (para 1.8) specifies a minimum clear visibility distance of 60m for 40mph roads.
(2) The sign has a disproportionately large NMV roundel for the stroke-width used.
(3) The sign has disproportionately small lettering on the supplementary plate compared to the roundel and stroke width sizes used. The supplementary plate’s x-height should = 3.2 x stroke width.
In short, this sign is littered with design errors!