Sorry for the delays in replies in forum. We have just recently created a Q&A page on our website, at Simul Support Exchange - Simul. Anyone looking for answers will get faster responses there.
We have just released our latest update. should fix dx12 issues for 4.24. We will release another update week incorporating these changes into 4.23, then possibly 4.22 if the demand is there.
For the wetness parameter, was disabled at some point, I’m not certain we will re-enable. But to get the precipitation we have a blueprint for get precipitation strength at position. You should be able to use to scale a value to your liking. Take a look at our YouTube tutorial on a similar aspect but incorporating dynamic snow. https://youtu.be/X9O92fZZS3s