For some of us, before any prototype announcement (now) is...

For some of us, before any prototype announcement (now) is already VERY successful. But to answer your question, if you want a confirmation before jumping on, then no, it still wouldn't be too late, because if it's successful, it can be applied to many other sectors, therefore, SP will still be relatively low and much de-risked. BUT your return would be a lot lower than what it would be if you bought prior to successful news.

But each to their own, do what suits your risk/reward profile.

I think in the case of a successful prototype and succeed in testing, we can easily see the SP go up another 100% from current SP.