Ya it might help a bit. I'm still on the reserved side when it comes to processing on the fly but I much prefer Android external box functionality to built in smart TV platforms. Sometimes you can run in to other things going on that another device ends up solving or handling better for reasons other than just PQ processing, so it can be worth a try. If you order from Amazon, you can always return it for a full refund if it doesn't improve things. Select a reason for return that puts the shipping cost on them and you're $0 out of pocket to try it. I've done that to try or compare devices I wasn't sure of.
I would say my X90L exceeds my CX in some ways, and not in others. Keep in mind it was basically the same price for a 20" bigger size, so prices weren't equal, but I'd say it's more tech trade offs than "better". It's better suited for a bright room with windows to deal with since it is capable of a significantly brighter image. That's probably the biggest thing. IMO OLED's are for light controlled rooms and LED's are for the brighter ones with windows. Generally speaking. With Local dimming on the 90L, I find the black levels are excellent and not far off OLED. Technically the CX wins out for being able to have pure black that OLED's are capable of, but I'm more than happy with the 90L's black levels. Near black details are much better resolved on the 90L but that's something OLED's have typically struggled with. There is some blooming on the 90L, but it doesn't bother me. Certainly not as much as the auto brightness limiting on the CX does. Those things seem to be subjective for what bothers users more, so ymmv. I find hockey is better on the 90L and watch it there typically. It handles motion better with less stutter and produces a brighter more accurate white. Can't say finer details or artifacts are an issue on either. I enjoy gaming on both and they're both fully capable of the new standards. I don't notice lost details on night scenes, and in reviews, the 90L was celebrated for handling this better than its comparable competitors. I did a ton of research and the X90L was the sweet spot for price and performance, but things may have changed.