Text and context

[Hermes777]

The script could be an attempt to craft a writing system for a previously oral-only language

I find it highly improbable. When an oral language starts to be written they use to take the written system of a near written language (by proximity, commerce, the language of their conquerons ...). There is no need to craft a whole system, it is easier to addapt a known system of reproducing sounds to the sounds of the oral language, it is a question of economy.

I think it is improbable too. After all, Ladin is Latin-like by any measure so the obvious thing to do is use the Latin script. As you say, there is no need to craft a whole system. Unless the script is meant to look antique, perhaps, and is posing as an old Latin script? Again: improbable. 

But I can't find any probable reason to create a new script in any scenario, so whatever the truth it is likely to be improbable. 

Still, one known scenario where people might go to the trouble of creating a new script is when bringing an oral tongue into writing. This might especially be the case if it is felt existing scripts don't capture the phonology of the oral language. I note that by some studies many of the peculiarities of Voynichese might be explained as phonic systems and transformations based on euphony and other phonic considerations. I also note the shifting "dialects" of Voynichese - Ladin actually being a cluster of kindred dialects. That is, the ms. might reflect two (or more) dialects of Ladin. 

But we know from history that when Ladin did start to be written down, the Roman script proved perfectly adequate. I admit I don't have any evidence the Ladin ever sought or ever experimented with a distinct script.