I've been chasing that question for a couple months, and unfortunately there is little to go on. All the testing of GPUs is focused on gaming, and has little to do with Adobe products.
The best resource currently is a Lightroom Benchmark by Puget Systems.
Details here:
https://www.pugetsystems.com/pugetbench/creators/lightroom-classic/Test results here:
https://www.pugetsystems.com/pugetbench/results/compare/Puget%20Bench%20for%20Lightroom%20Classic/But even that benchmark has very limited data, and on only 7 GPUs (your 4060 not included).
For me, it's all about Denoise AI. It's so good that I've significantly increased my volume of high ISO shots. My current 3 year old Nvidia RTX 3070 can Denoise AI my Canon EOSR raw files in about 7 seconds. Not bad, but not great either when I've got a few hundred shots.
I want to know how much improvement I'd see if I upgrade that GPU. Can't get the answer from the Puget Benchmark or any other source. But if I want to know how much faster Cyberpunk 2077 will play on an Nvidia RTX 5090, the answer is there. The Puget Benchmark is fairly new and the database will continue to grow, so maybe in the future...
P.S. A warning: If you want to download and run the Puget Benchmark beware that it won't work if your Lightroom is not installed on the System C: drive. Mine is not. All my Adobe software is installed on a secondary drive so as to not bulk up my System drive image backups. LR, Photoshop, Bridge, ACR currently take up over 20GB, mostly due to all the AI "Models."
