in my opinion we already have a lot of Categories for one mission there are 5 (difficulty) * 2 Solo / Group -> 10 records. splitting this up into 2, 3, 4 will make a phantastic 5 * 5 -> 25(!!) Worldrecords per mission.
In my eye, the split from solo vs group is already not worth it and just made the leaderboard unreadable for new players. It`s also an part of the mission speedrun to check what the fastest way is, some are faster in solo (way less adds) and sometimes playing in group is faster (more possible skip but also a lot more adds). In the current way (only showing solo/group of the normal run) the leaderboard is no longer usefull / readable. better readable would be an switch of difficulty/groupsize. So you have an level in all difficulties on the main leaderboard and the when goining to the level you can switch between groupsize (like it is currently with the difficulty)
but this is only my view of this topic :)
I`m open for discussion and new ideas, but as an speedrunner the current leaderboard is confusing (especially for potential new speedrunners). I liked the old leaderboard much more