The gap between 240 and 360 refresh rate is negligible. A decent 360hz monitor costs about as much as super good 240hz monitor
A Good Example.
Another inexpensive sleeper upgrade you can get is going a generation up to a 5600x. I also agree, RAM upgrades are pretty important, as already said, ryzen likes super fast ram. A little pricey for ram, but this would be ideal.
ur gpu is a beast btw, use that shit into the ground, upgrade when it dies
edit: thats ddr5 ram, so disregard that unless u plan on upgrading ur mobo as well to support it (Which i'd recommend)