I own both Glock 34 Gen 4 & 5. I recently purchased the Jager guide rod for my Gen 4. I was planning on using same guide rod for my Gen 5 before I read this post. The Gen 4 guide rod fits the Gen 5. I don’t see why it wouldn’t work.
I had my CGW parts installed by CJ MAVEN. He ended up using the stock hammer with CGW disco. My trigger take up is greatly reduced. His price for the install and turnaround time was amazing. It be worth talking to him to see what he can do.