WowAce

I've tried many things, like removing some categories, closing some groups etc ...

But activating profiling showed me some valuable information : more than 99% of the time spent was spent in sort operations
e.g mount group total time 997 sort time 994 i think there is a flaw in your sorting 

anotheer thing, don't know why there are regular scans even when addon not displayed (continuously showing debug in text chat) maybe it doesn't need so many updates 

Hope this can help cause i like the addon it was slow before shadowlands but now it is unusable ;'(

Hey, thx for the quick response 
For the second part i discovered it was related to enabling tooltip tries, so moving mouse over anything will cause some checks seems perfectly normal 
I read the github issue n°100 you linked and had a hard time to change order (when talking ux i want to click on the column header to change the sort order but in fact it's just above -_- been struggling with it since long in fact )

Now i'm back to order by name (which seems the default i guess ) and OMG it's day & night now it works perfectly !!!!

So it's clearly related to sort order
what has changed ? overall  time is down by 96% but the observation stays the same
e.G addGroup(¨Pet) took 52ms Sort 51.2 ms Iteration 0.35 Tooltip: 0.46 

what ever sort we pick it takes almost all the cpu time but if selecting another sort column than name it then becomes hugely inefficient

Hope this will help you track down the problem

Thanks, I agree that needs to be improved and I'll look into it as soon as I'm able.

For the UX change you proposed, I've created a separate issue here: https://github.com/WowRarity/Rarity/issues/392

The sorting performance being horrendously slow should largely be fixed in the latest release. Sorting by zone is a bit slow, but regardless approximately as fast as the previously fastest sort method, sorting by name.