Sure but these problems got accentuated after implementing PictureLibrary because then even Photolab ended up in the same kind of compromise that Lightroom have had to cope with for decades. … and there is no way out of that if they don’t make the use of the local database optional but then a lot of the users would probably like me have to rely on PhotoMechanic or some other third party DAM-software that is more loosely coupled with Photolab than PictureLibrary is.
Well there is one way and that have been used in Lightroom the way Scott Kelby has written in his recommendations in several of his Lightroom bibles. From what I remember that recommendation was to never use full size 1:1 previews. Then scrolling was fast but the price still had to be paid as soon as you opened one image for editing.
It is the rendering of full size previews that kills the performance and nothing else really and sooner or later in the workflow of a converter with integrated image library that rendering has to take place when you develop images. The only way to escape that compromise is to use two separated application - one for culling and metadata jobs and one for image development - the first using just thumbnails that allows for really fast and efficient scrolling and the later using 1:1 images for jobs demanding full control of the tiniest details .