Lojban has a central planning committee, the BPFK, so there is no danger of "Proper Lojban" falling prey to this, although certainly there have been dialects of Lojban in the past which deliberately were not parseable. They don't last long; none of the Lojban tools work with their experiments, so network effects tend to keep unparseable dialects from becoming popular.

From the beginning, Lojban's design has included this feature. It would be pointless to learn as a language if you intend to extend it in that way.

There are, of course, ways to experimentally extend the language grammatically, as well as a process for changing the grammar, which has happened before via the BPFK. It evolves, but with planning and consideration.

I think the value of Lojban/Loglan in this space is having a language that a human can use to have a more natural interaction between themselves and computers. And also as a layer for translating formulaic text between natural languages.

Exactly. When you have a language no one actually realistically speaks, you can stuff whatever highfalutin ideas you want into it.

Just look at JavaScript

JavaScript cannot be ambiguous because there's a constant acid test: Does the machine find it ambiguous? If it does, it fails to parse. (If it parses, it wasn't ambiguous, but it still might mean something the programmer didn't intend.) That property will hold until we do something like embedding AI in the compiler.

Humans can deal with ambiguity. There are various reasons for humans to want to be ambiguous, and any natural language has to support that to be useful for day-to-day conversation. Loglan and Lojban might well escape that, if they're only ever used in contexts where ambiguity is not desired and will be repaired if it is found.

Think formal specifications, not love letters.

Isn't the automated insertion of semicolons to your detrimemt a result of ambiguity in the language, and the compiler forced to decide

The rules for automatic semicolon insertion are defined by the language spec.