Probably going to go unnoticed. Big ideas (to me)
1. Solve the Amp In A Room problem. I get that its different when outputting to recording. but the amp in a room inspires me to create in a major way. Let me hear (and feel) that and let the outputs to recording capture what I play. Like recording with amps.
2. The interface, from the toaster to Rig Manager, is still techy and obtuse. Think Apple. The Kemper is by far the product I most have to research the manual or tech details. And I have an H9-Pro Max, a Boss RC-10R, etc.
3. Headphones still don't sound great and I've tried so many high end ones and so many cab sim settings. I can still hear the digital, especially on single note lines. Create the best headphone cab sim and the home studio / home practice world would light on fire. If one could hear a convincing live amp in headphones at 11pm...who knows what people could create.
4. For the love of whatever deity, hire someone to put tool-tips to describe what every single parameter dial does in Rig Manager. Its text in software, like the cheapest thing. Junior programmer level.