How do you actually use the new Pose library?

Maybe I’m just dumb but I can’t for the life of me figure out how to effectively use the new Pose library. To add a pose you select bones and add to pose library, simple yes, but then what if you want to change the pose?
There is no update pose button there is no replace button you got to delete the pose create new one and rename it again. In the original pose library you just press plus and replace.
Also the thumbnail, why is it I can’t use viewport for the thumbnail and also have to do the same steps as stated above just to change the thumbnail.

Also if you want to apply the pose you got to enter pose mode, while that doesn’t sound so bad its a really big pain when trying to fix bone weights as you constantly have to exit weight paint mode, select rig, enter pose mode, apply pose, exit pose mode, reselect the model and enter weight paint mode.
In the original pose library you just exit weight paint mode select rig and apply pose and right back to weight painting.

All in all the new pose library is cool and all especially for model and material assets for but posing is basically non functional.