Hi ayu
Thanks for the info and sorry for the delay in replying, We think we have found the main reason for poor performance.
It would seem that for each and every view, and that includes each view within a flex repeater, if icons are used then the entire icon library is downloaded. So, if a view has a single material icon used then each view will download the material icon SVG that is 286KB, if there are 100 views that’s 28MB
We have made a new icon library using just the icons we need and this is just 2KB, as you can imagine, things are a bit quicker and more responsive.