I can't speak to that particular RD but most any Shimano RD I've have has two spring tension holes in it. The default setting is the weaker of the two. I've not done it, but it can be changed if you have some mechanical aptitude. The Park document shows it. I don't know if it will help or not, but it's worth a try. I noticed long ago how the modern indexing RD have a softer spring setting than they were, say in the 80's. I never experienced any chain suck in my life until I started using a Deore LX 58something RD. .

https://www.parktool.com/en-us/blog/...lleur-overhaul