Since you're opening the door to adding new UI, maybe it's worth stepping back to consider the UI situation as it stands.
X-COM has UI issues, this much I think is clear to all. While OXC and OXCE/+ have made improvements in this area, oftentimes these improvements are awkward and hacky (clicking things in certain ways, using esoteric keyboard shortcuts). That's to be expected, since OXC only aspires to be a faithful re-implementation of the 90s games and the forks inherit that design mentality.
But with several mods nowadays extending the game's scope and complexity far beyond what X-COM originally offered, the shortcomings of the UI have become painfully clear, which is what prompted this topic. My question is, is it doable and/or desirable to go the distance and redesign both the management systems and the UI for said systems to improve the user experience as a whole? Is it worth the effort to chuck flawed elements from X-COM and replace them, or is it better to keep shoring them up as well as possible?