As a periodically heavy grinder of trove, even farming blocktron in 1 day months ago, getting 6 dragons in a week, etc.
I fail to see how U10 difficulty brings anything new to trovians' gaming experience, with the nerf of lesser topside cache's drops and how awkward it is to farm them after todays (december 14th) update there is no actual reason to farm 5 star dungeons at all after we reach cap gear.
So far, I still estimate (and so does many other fellow trovians) that for end game players topside will last at most 1 month for reaching max gear for the not so hardcore players and maybe 24h for the hardcores.
After that point, u10 and topside overall doesnt bring anything to the table, we will be even forced to go back to u9 prime worlds to get the resources needed to craft proper augments, and that means that there's no real reason to care about u10, it doesn't allow us to have a place when we can efficiently farm every resource.
And even if u did add back shadow gem box drop to u10 topside then there is the problem that the dungeons are so far from each other that the efficiency compared to u9, dust wise, is too low making u10 wortheless, even for tome grinding.
As far as for the current state of u10 now, it will be just another geode or bomber royale, an addition that doesn't bring anything useful to the majority of the player base that will just be appealing for a few of us.