The most obvious thing is just more DSP across the line.
I think the sound quality of Fractal's modeling is at a point where more DSP isn't really going to improve things dramatically anymore. But more DSP can be used for more blocks. More DSP would possibly allow Fractal not necessarily partition resources like they do now (dedicated core for reverb/delay, etc...). You could maybe do things like run more than 2 amp blocks simultaneously.
A wish I posted a while back was to have something I call "global path/grid". It would be like an evolution of global blocks/dedicated cores/spill over, gapless switching and templates. It would be a mini grid of multiple blocks that the user makes in the global settings. This mini-grid gets abstracted away as a single block that the user can then place in their presets. For example, in all my presets, I want to use the same Amp, followed by the same delay and reverb with some parallel routing. I can make that path in this global settings and save it to the "global path block". Then for all my presets, I add the global path block wherever I want. It would be one block that contains that whole amp, delay, reverb path. It would be the same in whatever preset uses that global path block. And this block would be the only one that runs on it's own dedicated core so it doesn't cost that much DSP in each preset.