There isn't a definitive answer, because sometimes you just have to try something and see how it plays out.

You can get the same added spring tension from any Shimano Shadow derailleur, and the Deore level will save you some coin:

https://www.universalcycles.com/shop...s.php?id=76560

Also helpful is to avoid back-pedaling in rough terrain. And possibly it can help to minimize chain slack by shifting into largest sprockets before a bouncy descent.

A more sure solution is to upgrade to 1x10 with a clutch derailleur and a chain guide, but that's an expensive can of worms that has you essentially replacing your entire drive train. Two of my friends have done that though -- going from 1x9 to 1x10 mainly for the option of a clutch derailleur.