Any luck using eSpeak NG with JAWS?

[TMaestro75]

Hi everyone,
Sorry if this kind of post doesn't belong here; I'm still learning this GitHub thing.
I recently spent a few days using only NVDA, while I was waiting for a JAWS update. I used eSpeak for Icelandic text. I've now gotten to the point where I am using the sandro variant with rate boost turned on, with the rate at 35. This makes it a lot quicker for me to navigate through text in Icelandic. This rate setting is way faster than anything I can achieve with the old eSpeak from 2015 that still had solid SAPI5 support, all be it a 32-bit one.
I'd really love to be able to do a similar thing with JAWS. Seems the only way to get JAWS talking to eSpeak NG is through SAPI 5, so I experimented with the registry, and the latest eSpeak NG December release build.
I didn't know what to add to the voice token in the registry, so I settled on the default value, the CLSID and the VoiceName value. It actually spoke, but there are major problems. First of all, the speech still cuts off before it can finish whatever text it is speaking. More importantly however, the speech rate slider does absolutely nothing, and rate boost can't be turned on of course.
Does anybody know what I would have to do to make this work? Are there things I can add to the registry, or would I have to modify the code and build a custom version of eSpeak NG by myself? I've no idea where to begin if I have to start modifying the source code. I've done some programming before, but nothing on this scale.

Best regards
Theo