I also have a Gweike G2 Pro 30W, using the 150mm lens.
I didn’t do a ton of 3D-Sliced relief engravings, but had good initial results with those settings:
- Medium Speed
- Max Power (because I’m impatient)
- 500-1000 passes.
- Low Frequency for more ablation. Generally, a lower frequency means that the fiber source charges up longer for each pulse, leading to higher power output. (Think of the frequency as the grit of sandpaper)
As Jack pointed out, there is a specific sweet-spot, where the laser emits the most power. But I’m not sure where that is on the Gweike.
You won’t find the Q-Pulse setting on the G2 Pro. It’s a Fiber source with a fixed Pulselength.
Cleanup Pass after 20 passes:
I’m happy to share my Material Library. Use it at your own risk! 
Note: Some of the Cut settings use way more passes than needed. When cutting, I just let the job run until it cuts through.
Gweike-G2Pro-30W-150mm-Aa.clb (20.0 KB)
Be prepared for long running jobs (1-3 hours, or more), and make sure you have an adequate exhaust system connected. You don’t want to breathe in the ablated brass particles!
I’m curious to see your results, and happy to help improve them if you can share what you discover!