Origin of the Shield Shape in the Solar Folio of the f85-86 Foldout

[Dobri]

We can also consider the initial  "Um" to represent an entire word.
By searching in Cappelli:
 verum, - virum, - vestrum

 utrum, - unum, - verbum

It is a possibility indeed and ydain could be a distinct vord in <1r.9>, because ydain occurs as a distinct vord also in <13v.8>, <14v.1>, <16r.8>, <33v.1>, and <75r.20> but not as a paragraph starter.

However, on the remaining 2-out-of-8 occasions ydain occurs in the first vord in each one of the two paragraphs in You are not allowed to view links. Register or Login to view. and has k as a prefix: kydainy in <2r.1>, and kydain in <2r.8>.

What if k is 'Um'?

Food for thought: If the Beneventan approach is a part of the cipher design, then all gallows could possibly be ligatures of two letters.