What is known about the Hurrian "wa" compound signs?

Question

According to the classic Hethitisches Zeichenlexikon, Hurrian used a handful of special signs made by combining the WA (aka PI) sign with others: wa+ap, wa+i, wa+pí, wa+ú, wa+e, wa+u, wa+pu, wa+ip, wa+a. (HZL transliterates them u̯a_ap etc.)

The authors have this to say about those (p253, my translation):

For the sign u̯a_a appearing in Proto-Hattic, Hurrian, and Palaic word-forms and texts, only the traditional transliteration is given here. Due to the still-uncertain state of the art, a phonetic/phonological interpretation (like fa^?) is avoided. […] Palaic spellings of this sort likely come from Proto-Hattic influence […] The exact Lautwert must be determined in individual languages.

But this was published in 1989, and I haven't been able to find any more modern discussion of these signs. Has any consensus been reached since then? (And as a side note, what is this "Proto-Hattic" (protohattischen) they're talking about?)

Answer 1

Protohattisch is perhaps the Hattic language, the isolated languages which had been spoken on the territory of the Hittite kingdom before Hittites arrived and settled there. The language is known from toponyms and a very scarce corpus written in syllabic cuneiform which makes it decipherment still more problematic. Hittites used Hattic as a ritual language in the cults of some gods, and no historical stages (Proto-Hattic vs. Hattic proper) can be distinguished. Sometimes Hattic was called Proto-Hittite actually meaning ‘Pre-Hittite’, maybe “Protohethitisch” was simply misspelled as “Protohattish”. Generally speaking, there's a traditional confusion of the words ‘Hattic’ and ‘Hittite’, even the capital of the Hittite kingdom was called Hattusas.

As for the WA (PI) sign, it is discussed in detail on pages 21–23 of this book:
An Introduction to the Hurrian Language [2020, Ilse Wegner (Revised, edited, and reformatted by Allan R. Bomhard)] (downloadable, 1Mb). Since it's more than 2 pages of text, I cannot cite it all here, besides you'll probably know it better which is of greater relevance for you there. What I understood is WA (IP) was used for writing consonants w/f, and the vowel was determined by the sign that followed, the a of WA wasn't taken into account.

Answer 2

It seems that Hurrian scribes wanted to remove some of the inherent ambiguity of the cuneiform signs.
It can be noted that signs like gi+e also exist.
The sign PI = wa is extremely ambiguous and can be read pi, wa, we, wi, wu, which obviously is troublesome.
Personally, I don't believe in the theory that Hurrian had sounds like f or v. For example the word "mountain" *pabani has an equivalent as Urartian baban. Besides, Kurdish has a word bane "mountain". None of these words has f or v. Not to mention also Ancient Greek bounos.